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39 * \brief This file defines integrators for energy minimization
41 * \author Berk Hess <hess@kth.se>
42 * \author Erik Lindahl <erik@kth.se>
43 * \ingroup module_mdrun
56 #include "gromacs/commandline/filenm.h"
57 #include "gromacs/domdec/collect.h"
58 #include "gromacs/domdec/domdec.h"
59 #include "gromacs/domdec/domdec_struct.h"
60 #include "gromacs/domdec/partition.h"
61 #include "gromacs/ewald/pme.h"
62 #include "gromacs/fileio/confio.h"
63 #include "gromacs/fileio/mtxio.h"
64 #include "gromacs/gmxlib/network.h"
65 #include "gromacs/gmxlib/nrnb.h"
66 #include "gromacs/imd/imd.h"
67 #include "gromacs/linearalgebra/sparsematrix.h"
68 #include "gromacs/listed-forces/manage-threading.h"
69 #include "gromacs/math/functions.h"
70 #include "gromacs/math/vec.h"
71 #include "gromacs/mdlib/constr.h"
72 #include "gromacs/mdlib/force.h"
73 #include "gromacs/mdlib/forcerec.h"
74 #include "gromacs/mdlib/gmx_omp_nthreads.h"
75 #include "gromacs/mdlib/md_support.h"
76 #include "gromacs/mdlib/mdatoms.h"
77 #include "gromacs/mdlib/mdebin.h"
78 #include "gromacs/mdlib/mdrun.h"
79 #include "gromacs/mdlib/mdsetup.h"
80 #include "gromacs/mdlib/ns.h"
81 #include "gromacs/mdlib/shellfc.h"
82 #include "gromacs/mdlib/sim_util.h"
83 #include "gromacs/mdlib/tgroup.h"
84 #include "gromacs/mdlib/trajectory_writing.h"
85 #include "gromacs/mdlib/update.h"
86 #include "gromacs/mdlib/vsite.h"
87 #include "gromacs/mdtypes/commrec.h"
88 #include "gromacs/mdtypes/inputrec.h"
89 #include "gromacs/mdtypes/md_enums.h"
90 #include "gromacs/mdtypes/state.h"
91 #include "gromacs/pbcutil/mshift.h"
92 #include "gromacs/pbcutil/pbc.h"
93 #include "gromacs/timing/wallcycle.h"
94 #include "gromacs/timing/walltime_accounting.h"
95 #include "gromacs/topology/mtop_util.h"
96 #include "gromacs/topology/topology.h"
97 #include "gromacs/utility/cstringutil.h"
98 #include "gromacs/utility/exceptions.h"
99 #include "gromacs/utility/fatalerror.h"
100 #include "gromacs/utility/logger.h"
101 #include "gromacs/utility/smalloc.h"
103 #include "integrator.h"
105 //! Utility structure for manipulating states during EM
107 //! Copy of the global state
113 //! Norm of the force
121 //! Print the EM starting conditions
122 static void print_em_start(FILE *fplog,
124 gmx_walltime_accounting_t walltime_accounting,
125 gmx_wallcycle_t wcycle,
128 walltime_accounting_start_time(walltime_accounting);
129 wallcycle_start(wcycle, ewcRUN);
130 print_start(fplog, cr, walltime_accounting, name);
133 //! Stop counting time for EM
134 static void em_time_end(gmx_walltime_accounting_t walltime_accounting,
135 gmx_wallcycle_t wcycle)
137 wallcycle_stop(wcycle, ewcRUN);
139 walltime_accounting_end_time(walltime_accounting);
142 //! Printing a log file and console header
143 static void sp_header(FILE *out, const char *minimizer, real ftol, int nsteps)
146 fprintf(out, "%s:\n", minimizer);
147 fprintf(out, " Tolerance (Fmax) = %12.5e\n", ftol);
148 fprintf(out, " Number of steps = %12d\n", nsteps);
151 //! Print warning message
152 static void warn_step(FILE *fp,
158 constexpr bool realIsDouble = GMX_DOUBLE;
161 if (!std::isfinite(fmax))
164 "\nEnergy minimization has stopped because the force "
165 "on at least one atom is not finite. This usually means "
166 "atoms are overlapping. Modify the input coordinates to "
167 "remove atom overlap or use soft-core potentials with "
168 "the free energy code to avoid infinite forces.\n%s",
170 "You could also be lucky that switching to double precision "
171 "is sufficient to obtain finite forces.\n" :
177 "\nEnergy minimization reached the maximum number "
178 "of steps before the forces reached the requested "
179 "precision Fmax < %g.\n", ftol);
184 "\nEnergy minimization has stopped, but the forces have "
185 "not converged to the requested precision Fmax < %g (which "
186 "may not be possible for your system). It stopped "
187 "because the algorithm tried to make a new step whose size "
188 "was too small, or there was no change in the energy since "
189 "last step. Either way, we regard the minimization as "
190 "converged to within the available machine precision, "
191 "given your starting configuration and EM parameters.\n%s%s",
194 "\nDouble precision normally gives you higher accuracy, but "
195 "this is often not needed for preparing to run molecular "
199 "You might need to increase your constraint accuracy, or turn\n"
200 "off constraints altogether (set constraints = none in mdp file)\n" :
204 fputs(wrap_lines(buffer, 78, 0, FALSE), stderr);
205 fputs(wrap_lines(buffer, 78, 0, FALSE), fp);
208 //! Print message about convergence of the EM
209 static void print_converged(FILE *fp, const char *alg, real ftol,
210 int64_t count, gmx_bool bDone, int64_t nsteps,
211 const em_state_t *ems, double sqrtNumAtoms)
213 char buf[STEPSTRSIZE];
217 fprintf(fp, "\n%s converged to Fmax < %g in %s steps\n",
218 alg, ftol, gmx_step_str(count, buf));
220 else if (count < nsteps)
222 fprintf(fp, "\n%s converged to machine precision in %s steps,\n"
223 "but did not reach the requested Fmax < %g.\n",
224 alg, gmx_step_str(count, buf), ftol);
228 fprintf(fp, "\n%s did not converge to Fmax < %g in %s steps.\n",
229 alg, ftol, gmx_step_str(count, buf));
233 fprintf(fp, "Potential Energy = %21.14e\n", ems->epot);
234 fprintf(fp, "Maximum force = %21.14e on atom %d\n", ems->fmax, ems->a_fmax + 1);
235 fprintf(fp, "Norm of force = %21.14e\n", ems->fnorm/sqrtNumAtoms);
237 fprintf(fp, "Potential Energy = %14.7e\n", ems->epot);
238 fprintf(fp, "Maximum force = %14.7e on atom %d\n", ems->fmax, ems->a_fmax + 1);
239 fprintf(fp, "Norm of force = %14.7e\n", ems->fnorm/sqrtNumAtoms);
243 //! Compute the norm and max of the force array in parallel
244 static void get_f_norm_max(const t_commrec *cr,
245 t_grpopts *opts, t_mdatoms *mdatoms, const rvec *f,
246 real *fnorm, real *fmax, int *a_fmax)
250 int la_max, a_max, start, end, i, m, gf;
252 /* This routine finds the largest force and returns it.
253 * On parallel machines the global max is taken.
259 end = mdatoms->homenr;
260 if (mdatoms->cFREEZE)
262 for (i = start; i < end; i++)
264 gf = mdatoms->cFREEZE[i];
266 for (m = 0; m < DIM; m++)
268 if (!opts->nFreeze[gf][m])
270 fam += gmx::square(f[i][m]);
283 for (i = start; i < end; i++)
295 if (la_max >= 0 && DOMAINDECOMP(cr))
297 a_max = cr->dd->globalAtomIndices[la_max];
305 snew(sum, 2*cr->nnodes+1);
306 sum[2*cr->nodeid] = fmax2;
307 sum[2*cr->nodeid+1] = a_max;
308 sum[2*cr->nnodes] = fnorm2;
309 gmx_sumd(2*cr->nnodes+1, sum, cr);
310 fnorm2 = sum[2*cr->nnodes];
311 /* Determine the global maximum */
312 for (i = 0; i < cr->nnodes; i++)
314 if (sum[2*i] > fmax2)
317 a_max = gmx::roundToInt(sum[2*i+1]);
325 *fnorm = sqrt(fnorm2);
337 //! Compute the norm of the force
338 static void get_state_f_norm_max(const t_commrec *cr,
339 t_grpopts *opts, t_mdatoms *mdatoms,
342 get_f_norm_max(cr, opts, mdatoms, as_rvec_array(ems->f.data()),
343 &ems->fnorm, &ems->fmax, &ems->a_fmax);
346 //! Initialize the energy minimization
347 static void init_em(FILE *fplog,
348 const gmx::MDLogger &mdlog,
351 const gmx_multisim_t *ms,
352 gmx::IMDOutputProvider *outputProvider,
354 const MdrunOptions &mdrunOptions,
355 t_state *state_global, gmx_mtop_t *top_global,
356 em_state_t *ems, gmx_localtop_t **top,
357 t_nrnb *nrnb, rvec mu_tot,
358 t_forcerec *fr, gmx_enerdata_t **enerd,
359 t_graph **graph, gmx::MDAtoms *mdAtoms, gmx_global_stat_t *gstat,
360 gmx_vsite_t *vsite, gmx::Constraints *constr, gmx_shellfc_t **shellfc,
361 int nfile, const t_filenm fnm[],
362 gmx_mdoutf_t *outf, t_mdebin **mdebin,
363 gmx_wallcycle_t wcycle)
369 fprintf(fplog, "Initiating %s\n", title);
374 state_global->ngtc = 0;
376 /* Initialize lambda variables */
377 initialize_lambdas(fplog, ir, &(state_global->fep_state), state_global->lambda, nullptr);
382 /* Interactive molecular dynamics */
383 init_IMD(ir, cr, ms, top_global, fplog, 1,
384 MASTER(cr) ? as_rvec_array(state_global->x.data()) : nullptr,
385 nfile, fnm, nullptr, mdrunOptions);
389 GMX_ASSERT(shellfc != nullptr, "With NM we always support shells");
391 *shellfc = init_shell_flexcon(stdout,
393 constr ? constr->numFlexibleConstraints() : 0,
399 GMX_ASSERT(EI_ENERGY_MINIMIZATION(ir->eI), "This else currently only handles energy minimizers, consider if your algorithm needs shell/flexible-constraint support");
401 /* With energy minimization, shells and flexible constraints are
402 * automatically minimized when treated like normal DOFS.
404 if (shellfc != nullptr)
410 auto mdatoms = mdAtoms->mdatoms();
411 if (DOMAINDECOMP(cr))
413 *top = dd_init_local_top(top_global);
415 dd_init_local_state(cr->dd, state_global, &ems->s);
417 /* Distribute the charge groups over the nodes from the master node */
418 dd_partition_system(fplog, mdlog, ir->init_step, cr, TRUE, 1,
419 state_global, top_global, ir,
420 &ems->s, &ems->f, mdAtoms, *top,
422 nrnb, nullptr, FALSE);
423 dd_store_state(cr->dd, &ems->s);
429 state_change_natoms(state_global, state_global->natoms);
430 /* Just copy the state */
431 ems->s = *state_global;
432 state_change_natoms(&ems->s, ems->s.natoms);
433 /* We need to allocate one element extra, since we might use
434 * (unaligned) 4-wide SIMD loads to access rvec entries.
436 ems->f.resize(gmx::paddedRVecVectorSize(ems->s.natoms));
439 mdAlgorithmsSetupAtomData(cr, ir, top_global, *top, fr,
441 constr, vsite, shellfc ? *shellfc : nullptr);
445 set_vsite_top(vsite, *top, mdatoms);
449 update_mdatoms(mdAtoms->mdatoms(), ems->s.lambda[efptMASS]);
453 // TODO how should this cross-module support dependency be managed?
454 if (ir->eConstrAlg == econtSHAKE &&
455 gmx_mtop_ftype_count(top_global, F_CONSTR) > 0)
457 gmx_fatal(FARGS, "Can not do energy minimization with %s, use %s\n",
458 econstr_names[econtSHAKE], econstr_names[econtLINCS]);
461 if (!ir->bContinuation)
463 /* Constrain the starting coordinates */
465 constr->apply(TRUE, TRUE,
467 as_rvec_array(ems->s.x.data()),
468 as_rvec_array(ems->s.x.data()),
471 ems->s.lambda[efptFEP], &dvdl_constr,
472 nullptr, nullptr, gmx::ConstraintVariable::Positions);
478 *gstat = global_stat_init(ir);
485 *outf = init_mdoutf(fplog, nfile, fnm, mdrunOptions, cr, outputProvider, ir, top_global, nullptr, wcycle);
488 init_enerdata(top_global->groups.grps[egcENER].nr, ir->fepvals->n_lambda,
491 if (mdebin != nullptr)
493 /* Init bin for energy stuff */
494 *mdebin = init_mdebin(mdoutf_get_fp_ene(*outf), top_global, ir, nullptr);
498 calc_shifts(ems->s.box, fr->shift_vec);
501 //! Finalize the minimization
502 static void finish_em(const t_commrec *cr, gmx_mdoutf_t outf,
503 gmx_walltime_accounting_t walltime_accounting,
504 gmx_wallcycle_t wcycle)
506 if (!thisRankHasDuty(cr, DUTY_PME))
508 /* Tell the PME only node to finish */
509 gmx_pme_send_finish(cr);
514 em_time_end(walltime_accounting, wcycle);
517 //! Swap two different EM states during minimization
518 static void swap_em_state(em_state_t **ems1, em_state_t **ems2)
527 //! Save the EM trajectory
528 static void write_em_traj(FILE *fplog, const t_commrec *cr,
530 gmx_bool bX, gmx_bool bF, const char *confout,
531 gmx_mtop_t *top_global,
532 t_inputrec *ir, int64_t step,
534 t_state *state_global,
535 ObservablesHistory *observablesHistory)
541 mdof_flags |= MDOF_X;
545 mdof_flags |= MDOF_F;
548 /* If we want IMD output, set appropriate MDOF flag */
551 mdof_flags |= MDOF_IMD;
554 mdoutf_write_to_trajectory_files(fplog, cr, outf, mdof_flags,
555 top_global, step, static_cast<double>(step),
556 &state->s, state_global, observablesHistory,
559 if (confout != nullptr)
561 if (DOMAINDECOMP(cr))
563 /* If bX=true, x was collected to state_global in the call above */
566 gmx::ArrayRef<gmx::RVec> globalXRef = MASTER(cr) ? gmx::makeArrayRef(state_global->x) : gmx::EmptyArrayRef();
567 dd_collect_vec(cr->dd, &state->s, state->s.x, globalXRef);
572 /* Copy the local state pointer */
573 state_global = &state->s;
578 if (ir->ePBC != epbcNONE && !ir->bPeriodicMols && DOMAINDECOMP(cr))
580 /* Make molecules whole only for confout writing */
581 do_pbc_mtop(fplog, ir->ePBC, state->s.box, top_global,
582 as_rvec_array(state_global->x.data()));
585 write_sto_conf_mtop(confout,
586 *top_global->name, top_global,
587 as_rvec_array(state_global->x.data()), nullptr, ir->ePBC, state->s.box);
592 //! \brief Do one minimization step
594 // \returns true when the step succeeded, false when a constraint error occurred
595 static bool do_em_step(const t_commrec *cr,
596 t_inputrec *ir, t_mdatoms *md,
597 em_state_t *ems1, real a, const PaddedRVecVector *force,
599 gmx::Constraints *constr,
606 int nthreads gmx_unused;
608 bool validStep = true;
613 if (DOMAINDECOMP(cr) && s1->ddp_count != cr->dd->ddp_count)
615 gmx_incons("state mismatch in do_em_step");
618 s2->flags = s1->flags;
620 if (s2->natoms != s1->natoms)
622 state_change_natoms(s2, s1->natoms);
623 /* We need to allocate one element extra, since we might use
624 * (unaligned) 4-wide SIMD loads to access rvec entries.
626 ems2->f.resize(gmx::paddedRVecVectorSize(s2->natoms));
628 if (DOMAINDECOMP(cr) && s2->cg_gl.size() != s1->cg_gl.size())
630 s2->cg_gl.resize(s1->cg_gl.size());
633 copy_mat(s1->box, s2->box);
634 /* Copy free energy state */
635 s2->lambda = s1->lambda;
636 copy_mat(s1->box, s2->box);
641 nthreads = gmx_omp_nthreads_get(emntUpdate);
642 #pragma omp parallel num_threads(nthreads)
644 const rvec *x1 = as_rvec_array(s1->x.data());
645 rvec *x2 = as_rvec_array(s2->x.data());
646 const rvec *f = as_rvec_array(force->data());
649 #pragma omp for schedule(static) nowait
650 for (int i = start; i < end; i++)
658 for (int m = 0; m < DIM; m++)
660 if (ir->opts.nFreeze[gf][m])
666 x2[i][m] = x1[i][m] + a*f[i][m];
670 GMX_CATCH_ALL_AND_EXIT_WITH_FATAL_ERROR;
673 if (s2->flags & (1<<estCGP))
675 /* Copy the CG p vector */
676 const rvec *p1 = as_rvec_array(s1->cg_p.data());
677 rvec *p2 = as_rvec_array(s2->cg_p.data());
678 #pragma omp for schedule(static) nowait
679 for (int i = start; i < end; i++)
681 // Trivial OpenMP block that does not throw
682 copy_rvec(p1[i], p2[i]);
686 if (DOMAINDECOMP(cr))
688 s2->ddp_count = s1->ddp_count;
690 /* OpenMP does not supported unsigned loop variables */
691 #pragma omp for schedule(static) nowait
692 for (int i = 0; i < static_cast<int>(s2->cg_gl.size()); i++)
694 s2->cg_gl[i] = s1->cg_gl[i];
696 s2->ddp_count_cg_gl = s1->ddp_count_cg_gl;
704 constr->apply(TRUE, TRUE,
706 as_rvec_array(s1->x.data()), as_rvec_array(s2->x.data()),
708 s2->lambda[efptBONDED], &dvdl_constr,
709 nullptr, nullptr, gmx::ConstraintVariable::Positions);
713 /* This global reduction will affect performance at high
714 * parallelization, but we can not really avoid it.
715 * But usually EM is not run at high parallelization.
717 int reductionBuffer = static_cast<int>(!validStep);
718 gmx_sumi(1, &reductionBuffer, cr);
719 validStep = (reductionBuffer == 0);
722 // We should move this check to the different minimizers
723 if (!validStep && ir->eI != eiSteep)
725 gmx_fatal(FARGS, "The coordinates could not be constrained. Minimizer '%s' can not handle constraint failures, use minimizer '%s' before using '%s'.",
726 EI(ir->eI), EI(eiSteep), EI(ir->eI));
733 //! Prepare EM for using domain decomposition parallellization
734 static void em_dd_partition_system(FILE *fplog,
735 const gmx::MDLogger &mdlog,
736 int step, const t_commrec *cr,
737 gmx_mtop_t *top_global, t_inputrec *ir,
738 em_state_t *ems, gmx_localtop_t *top,
739 gmx::MDAtoms *mdAtoms, t_forcerec *fr,
740 gmx_vsite_t *vsite, gmx::Constraints *constr,
741 t_nrnb *nrnb, gmx_wallcycle_t wcycle)
743 /* Repartition the domain decomposition */
744 dd_partition_system(fplog, mdlog, step, cr, FALSE, 1,
745 nullptr, top_global, ir,
747 mdAtoms, top, fr, vsite, constr,
748 nrnb, wcycle, FALSE);
749 dd_store_state(cr->dd, &ems->s);
755 /*! \brief Class to handle the work of setting and doing an energy evaluation.
757 * This class is a mere aggregate of parameters to pass to evaluate an
758 * energy, so that future changes to names and types of them consume
759 * less time when refactoring other code.
761 * Aggregate initialization is used, for which the chief risk is that
762 * if a member is added at the end and not all initializer lists are
763 * updated, then the member will be value initialized, which will
764 * typically mean initialization to zero.
766 * We only want to construct one of these with an initializer list, so
767 * we explicitly delete the default constructor. */
768 class EnergyEvaluator
771 //! We only intend to construct such objects with an initializer list.
772 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
773 // Aspects of the C++11 spec changed after GCC 4.8.5, and
774 // compilation of the initializer list construction in
775 // runner.cpp fails in GCC 4.8.5.
776 EnergyEvaluator() = delete;
778 /*! \brief Evaluates an energy on the state in \c ems.
780 * \todo In practice, the same objects mu_tot, vir, and pres
781 * are always passed to this function, so we would rather have
782 * them as data members. However, their C-array types are
783 * unsuited for aggregate initialization. When the types
784 * improve, the call signature of this method can be reduced.
786 void run(em_state_t *ems, rvec mu_tot,
787 tensor vir, tensor pres,
788 int64_t count, gmx_bool bFirst);
789 //! Handles logging (deprecated).
792 const gmx::MDLogger &mdlog;
793 //! Handles communication.
795 //! Coordinates multi-simulations.
796 const gmx_multisim_t *ms;
797 //! Holds the simulation topology.
798 gmx_mtop_t *top_global;
799 //! Holds the domain topology.
801 //! User input options.
802 t_inputrec *inputrec;
803 //! Manages flop accounting.
805 //! Manages wall cycle accounting.
806 gmx_wallcycle_t wcycle;
807 //! Coordinates global reduction.
808 gmx_global_stat_t gstat;
809 //! Handles virtual sites.
811 //! Handles constraints.
812 gmx::Constraints *constr;
813 //! Handles strange things.
815 //! Molecular graph for SHAKE.
817 //! Per-atom data for this domain.
818 gmx::MDAtoms *mdAtoms;
819 //! Handles how to calculate the forces.
821 //! Stores the computed energies.
822 gmx_enerdata_t *enerd;
826 EnergyEvaluator::run(em_state_t *ems, rvec mu_tot,
827 tensor vir, tensor pres,
828 int64_t count, gmx_bool bFirst)
832 tensor force_vir, shake_vir, ekin;
833 real dvdl_constr, prescorr, enercorr, dvdlcorr;
836 /* Set the time to the initial time, the time does not change during EM */
837 t = inputrec->init_t;
840 (DOMAINDECOMP(cr) && ems->s.ddp_count < cr->dd->ddp_count))
842 /* This is the first state or an old state used before the last ns */
848 if (inputrec->nstlist > 0)
856 construct_vsites(vsite, as_rvec_array(ems->s.x.data()), 1, nullptr,
857 top->idef.iparams, top->idef.il,
858 fr->ePBC, fr->bMolPBC, cr, ems->s.box);
861 if (DOMAINDECOMP(cr) && bNS)
863 /* Repartition the domain decomposition */
864 em_dd_partition_system(fplog, mdlog, count, cr, top_global, inputrec,
865 ems, top, mdAtoms, fr, vsite, constr,
869 /* Calc force & energy on new trial position */
870 /* do_force always puts the charge groups in the box and shifts again
871 * We do not unshift, so molecules are always whole in congrad.c
873 do_force(fplog, cr, ms, inputrec, nullptr, nullptr,
874 count, nrnb, wcycle, top, &top_global->groups,
875 ems->s.box, ems->s.x, &ems->s.hist,
876 ems->f, force_vir, mdAtoms->mdatoms(), enerd, fcd,
877 ems->s.lambda, graph, fr, vsite, mu_tot, t, nullptr,
878 GMX_FORCE_STATECHANGED | GMX_FORCE_ALLFORCES |
879 GMX_FORCE_VIRIAL | GMX_FORCE_ENERGY |
880 (bNS ? GMX_FORCE_NS : 0),
882 DdOpenBalanceRegionBeforeForceComputation::yes :
883 DdOpenBalanceRegionBeforeForceComputation::no,
885 DdCloseBalanceRegionAfterForceComputation::yes :
886 DdCloseBalanceRegionAfterForceComputation::no);
888 /* Clear the unused shake virial and pressure */
889 clear_mat(shake_vir);
892 /* Communicate stuff when parallel */
893 if (PAR(cr) && inputrec->eI != eiNM)
895 wallcycle_start(wcycle, ewcMoveE);
897 global_stat(gstat, cr, enerd, force_vir, shake_vir, mu_tot,
898 inputrec, nullptr, nullptr, nullptr, 1, &terminate,
904 wallcycle_stop(wcycle, ewcMoveE);
907 /* Calculate long range corrections to pressure and energy */
908 calc_dispcorr(inputrec, fr, ems->s.box, ems->s.lambda[efptVDW],
909 pres, force_vir, &prescorr, &enercorr, &dvdlcorr);
910 enerd->term[F_DISPCORR] = enercorr;
911 enerd->term[F_EPOT] += enercorr;
912 enerd->term[F_PRES] += prescorr;
913 enerd->term[F_DVDL] += dvdlcorr;
915 ems->epot = enerd->term[F_EPOT];
919 /* Project out the constraint components of the force */
921 rvec *f_rvec = as_rvec_array(ems->f.data());
922 constr->apply(FALSE, FALSE,
924 as_rvec_array(ems->s.x.data()), f_rvec, f_rvec,
926 ems->s.lambda[efptBONDED], &dvdl_constr,
927 nullptr, &shake_vir, gmx::ConstraintVariable::ForceDispl);
928 enerd->term[F_DVDL_CONSTR] += dvdl_constr;
929 m_add(force_vir, shake_vir, vir);
933 copy_mat(force_vir, vir);
937 enerd->term[F_PRES] =
938 calc_pres(fr->ePBC, inputrec->nwall, ems->s.box, ekin, vir, pres);
940 sum_dhdl(enerd, ems->s.lambda, inputrec->fepvals);
942 if (EI_ENERGY_MINIMIZATION(inputrec->eI))
944 get_state_f_norm_max(cr, &(inputrec->opts), mdAtoms->mdatoms(), ems);
950 //! Parallel utility summing energies and forces
951 static double reorder_partsum(const t_commrec *cr, t_grpopts *opts, t_mdatoms *mdatoms,
952 gmx_mtop_t *top_global,
953 em_state_t *s_min, em_state_t *s_b)
956 int ncg, *cg_gl, *index, c, cg, i, a0, a1, a, gf, m;
958 unsigned char *grpnrFREEZE;
962 fprintf(debug, "Doing reorder_partsum\n");
965 const rvec *fm = as_rvec_array(s_min->f.data());
966 const rvec *fb = as_rvec_array(s_b->f.data());
968 cgs_gl = dd_charge_groups_global(cr->dd);
969 index = cgs_gl->index;
971 /* Collect fm in a global vector fmg.
972 * This conflicts with the spirit of domain decomposition,
973 * but to fully optimize this a much more complicated algorithm is required.
976 snew(fmg, top_global->natoms);
978 ncg = s_min->s.cg_gl.size();
979 cg_gl = s_min->s.cg_gl.data();
981 for (c = 0; c < ncg; c++)
986 for (a = a0; a < a1; a++)
988 copy_rvec(fm[i], fmg[a]);
992 gmx_sum(top_global->natoms*3, fmg[0], cr);
994 /* Now we will determine the part of the sum for the cgs in state s_b */
995 ncg = s_b->s.cg_gl.size();
996 cg_gl = s_b->s.cg_gl.data();
1000 grpnrFREEZE = top_global->groups.grpnr[egcFREEZE];
1001 for (c = 0; c < ncg; c++)
1006 for (a = a0; a < a1; a++)
1008 if (mdatoms->cFREEZE && grpnrFREEZE)
1010 gf = grpnrFREEZE[i];
1012 for (m = 0; m < DIM; m++)
1014 if (!opts->nFreeze[gf][m])
1016 partsum += (fb[i][m] - fmg[a][m])*fb[i][m];
1028 //! Print some stuff, like beta, whatever that means.
1029 static real pr_beta(const t_commrec *cr, t_grpopts *opts, t_mdatoms *mdatoms,
1030 gmx_mtop_t *top_global,
1031 em_state_t *s_min, em_state_t *s_b)
1035 /* This is just the classical Polak-Ribiere calculation of beta;
1036 * it looks a bit complicated since we take freeze groups into account,
1037 * and might have to sum it in parallel runs.
1040 if (!DOMAINDECOMP(cr) ||
1041 (s_min->s.ddp_count == cr->dd->ddp_count &&
1042 s_b->s.ddp_count == cr->dd->ddp_count))
1044 const rvec *fm = as_rvec_array(s_min->f.data());
1045 const rvec *fb = as_rvec_array(s_b->f.data());
1048 /* This part of code can be incorrect with DD,
1049 * since the atom ordering in s_b and s_min might differ.
1051 for (int i = 0; i < mdatoms->homenr; i++)
1053 if (mdatoms->cFREEZE)
1055 gf = mdatoms->cFREEZE[i];
1057 for (int m = 0; m < DIM; m++)
1059 if (!opts->nFreeze[gf][m])
1061 sum += (fb[i][m] - fm[i][m])*fb[i][m];
1068 /* We need to reorder cgs while summing */
1069 sum = reorder_partsum(cr, opts, mdatoms, top_global, s_min, s_b);
1073 gmx_sumd(1, &sum, cr);
1076 return sum/gmx::square(s_min->fnorm);
1085 const char *CG = "Polak-Ribiere Conjugate Gradients";
1087 gmx_localtop_t *top;
1088 gmx_enerdata_t *enerd;
1089 gmx_global_stat_t gstat;
1091 double tmp, minstep;
1093 real a, b, c, beta = 0.0;
1097 gmx_bool converged, foundlower;
1099 gmx_bool do_log = FALSE, do_ene = FALSE, do_x, do_f;
1101 int number_steps, neval = 0, nstcg = inputrec->nstcgsteep;
1103 int m, step, nminstep;
1104 auto mdatoms = mdAtoms->mdatoms();
1110 // In CG, the state is extended with a search direction
1111 state_global->flags |= (1<<estCGP);
1113 // Ensure the extra per-atom state array gets allocated
1114 state_change_natoms(state_global, state_global->natoms);
1116 // Initialize the search direction to zero
1117 for (RVec &cg_p : state_global->cg_p)
1123 /* Create 4 states on the stack and extract pointers that we will swap */
1124 em_state_t s0 {}, s1 {}, s2 {}, s3 {};
1125 em_state_t *s_min = &s0;
1126 em_state_t *s_a = &s1;
1127 em_state_t *s_b = &s2;
1128 em_state_t *s_c = &s3;
1130 /* Init em and store the local state in s_min */
1131 init_em(fplog, mdlog, CG, cr, ms, outputProvider, inputrec, mdrunOptions,
1132 state_global, top_global, s_min, &top,
1133 nrnb, mu_tot, fr, &enerd, &graph, mdAtoms, &gstat,
1134 vsite, constr, nullptr,
1135 nfile, fnm, &outf, &mdebin, wcycle);
1137 /* Print to log file */
1138 print_em_start(fplog, cr, walltime_accounting, wcycle, CG);
1140 /* Max number of steps */
1141 number_steps = inputrec->nsteps;
1145 sp_header(stderr, CG, inputrec->em_tol, number_steps);
1149 sp_header(fplog, CG, inputrec->em_tol, number_steps);
1152 EnergyEvaluator energyEvaluator {
1153 fplog, mdlog, cr, ms,
1155 inputrec, nrnb, wcycle, gstat,
1156 vsite, constr, fcd, graph,
1159 /* Call the force routine and some auxiliary (neighboursearching etc.) */
1160 /* do_force always puts the charge groups in the box and shifts again
1161 * We do not unshift, so molecules are always whole in congrad.c
1163 energyEvaluator.run(s_min, mu_tot, vir, pres, -1, TRUE);
1167 /* Copy stuff to the energy bin for easy printing etc. */
1168 upd_mdebin(mdebin, FALSE, FALSE, static_cast<double>(step),
1169 mdatoms->tmass, enerd, &s_min->s, inputrec->fepvals, inputrec->expandedvals, s_min->s.box,
1170 nullptr, nullptr, vir, pres, nullptr, mu_tot, constr);
1172 print_ebin_header(fplog, step, step);
1173 print_ebin(mdoutf_get_fp_ene(outf), TRUE, FALSE, FALSE, fplog, step, step, eprNORMAL,
1174 mdebin, fcd, &(top_global->groups), &(inputrec->opts), nullptr);
1177 /* Estimate/guess the initial stepsize */
1178 stepsize = inputrec->em_stepsize/s_min->fnorm;
1182 double sqrtNumAtoms = sqrt(static_cast<double>(state_global->natoms));
1183 fprintf(stderr, " F-max = %12.5e on atom %d\n",
1184 s_min->fmax, s_min->a_fmax+1);
1185 fprintf(stderr, " F-Norm = %12.5e\n",
1186 s_min->fnorm/sqrtNumAtoms);
1187 fprintf(stderr, "\n");
1188 /* and copy to the log file too... */
1189 fprintf(fplog, " F-max = %12.5e on atom %d\n",
1190 s_min->fmax, s_min->a_fmax+1);
1191 fprintf(fplog, " F-Norm = %12.5e\n",
1192 s_min->fnorm/sqrtNumAtoms);
1193 fprintf(fplog, "\n");
1195 /* Start the loop over CG steps.
1196 * Each successful step is counted, and we continue until
1197 * we either converge or reach the max number of steps.
1200 for (step = 0; (number_steps < 0 || step <= number_steps) && !converged; step++)
1203 /* start taking steps in a new direction
1204 * First time we enter the routine, beta=0, and the direction is
1205 * simply the negative gradient.
1208 /* Calculate the new direction in p, and the gradient in this direction, gpa */
1209 rvec *pm = as_rvec_array(s_min->s.cg_p.data());
1210 const rvec *sfm = as_rvec_array(s_min->f.data());
1213 for (int i = 0; i < mdatoms->homenr; i++)
1215 if (mdatoms->cFREEZE)
1217 gf = mdatoms->cFREEZE[i];
1219 for (m = 0; m < DIM; m++)
1221 if (!inputrec->opts.nFreeze[gf][m])
1223 pm[i][m] = sfm[i][m] + beta*pm[i][m];
1224 gpa -= pm[i][m]*sfm[i][m];
1225 /* f is negative gradient, thus the sign */
1234 /* Sum the gradient along the line across CPUs */
1237 gmx_sumd(1, &gpa, cr);
1240 /* Calculate the norm of the search vector */
1241 get_f_norm_max(cr, &(inputrec->opts), mdatoms, pm, &pnorm, nullptr, nullptr);
1243 /* Just in case stepsize reaches zero due to numerical precision... */
1246 stepsize = inputrec->em_stepsize/pnorm;
1250 * Double check the value of the derivative in the search direction.
1251 * If it is positive it must be due to the old information in the
1252 * CG formula, so just remove that and start over with beta=0.
1253 * This corresponds to a steepest descent step.
1258 step--; /* Don't count this step since we are restarting */
1259 continue; /* Go back to the beginning of the big for-loop */
1262 /* Calculate minimum allowed stepsize, before the average (norm)
1263 * relative change in coordinate is smaller than precision
1266 for (int i = 0; i < mdatoms->homenr; i++)
1268 for (m = 0; m < DIM; m++)
1270 tmp = fabs(s_min->s.x[i][m]);
1279 /* Add up from all CPUs */
1282 gmx_sumd(1, &minstep, cr);
1285 minstep = GMX_REAL_EPS/sqrt(minstep/(3*top_global->natoms));
1287 if (stepsize < minstep)
1293 /* Write coordinates if necessary */
1294 do_x = do_per_step(step, inputrec->nstxout);
1295 do_f = do_per_step(step, inputrec->nstfout);
1297 write_em_traj(fplog, cr, outf, do_x, do_f, nullptr,
1298 top_global, inputrec, step,
1299 s_min, state_global, observablesHistory);
1301 /* Take a step downhill.
1302 * In theory, we should minimize the function along this direction.
1303 * That is quite possible, but it turns out to take 5-10 function evaluations
1304 * for each line. However, we dont really need to find the exact minimum -
1305 * it is much better to start a new CG step in a modified direction as soon
1306 * as we are close to it. This will save a lot of energy evaluations.
1308 * In practice, we just try to take a single step.
1309 * If it worked (i.e. lowered the energy), we increase the stepsize but
1310 * the continue straight to the next CG step without trying to find any minimum.
1311 * If it didn't work (higher energy), there must be a minimum somewhere between
1312 * the old position and the new one.
1314 * Due to the finite numerical accuracy, it turns out that it is a good idea
1315 * to even accept a SMALL increase in energy, if the derivative is still downhill.
1316 * This leads to lower final energies in the tests I've done. / Erik
1318 s_a->epot = s_min->epot;
1320 c = a + stepsize; /* reference position along line is zero */
1322 if (DOMAINDECOMP(cr) && s_min->s.ddp_count < cr->dd->ddp_count)
1324 em_dd_partition_system(fplog, mdlog, step, cr, top_global, inputrec,
1325 s_min, top, mdAtoms, fr, vsite, constr,
1329 /* Take a trial step (new coords in s_c) */
1330 do_em_step(cr, inputrec, mdatoms, s_min, c, &s_min->s.cg_p, s_c,
1334 /* Calculate energy for the trial step */
1335 energyEvaluator.run(s_c, mu_tot, vir, pres, -1, FALSE);
1337 /* Calc derivative along line */
1338 const rvec *pc = as_rvec_array(s_c->s.cg_p.data());
1339 const rvec *sfc = as_rvec_array(s_c->f.data());
1341 for (int i = 0; i < mdatoms->homenr; i++)
1343 for (m = 0; m < DIM; m++)
1345 gpc -= pc[i][m]*sfc[i][m]; /* f is negative gradient, thus the sign */
1348 /* Sum the gradient along the line across CPUs */
1351 gmx_sumd(1, &gpc, cr);
1354 /* This is the max amount of increase in energy we tolerate */
1355 tmp = std::sqrt(GMX_REAL_EPS)*fabs(s_a->epot);
1357 /* Accept the step if the energy is lower, or if it is not significantly higher
1358 * and the line derivative is still negative.
1360 if (s_c->epot < s_a->epot || (gpc < 0 && s_c->epot < (s_a->epot + tmp)))
1363 /* Great, we found a better energy. Increase step for next iteration
1364 * if we are still going down, decrease it otherwise
1368 stepsize *= 1.618034; /* The golden section */
1372 stepsize *= 0.618034; /* 1/golden section */
1377 /* New energy is the same or higher. We will have to do some work
1378 * to find a smaller value in the interval. Take smaller step next time!
1381 stepsize *= 0.618034;
1387 /* OK, if we didn't find a lower value we will have to locate one now - there must
1388 * be one in the interval [a=0,c].
1389 * The same thing is valid here, though: Don't spend dozens of iterations to find
1390 * the line minimum. We try to interpolate based on the derivative at the endpoints,
1391 * and only continue until we find a lower value. In most cases this means 1-2 iterations.
1393 * I also have a safeguard for potentially really pathological functions so we never
1394 * take more than 20 steps before we give up ...
1396 * If we already found a lower value we just skip this step and continue to the update.
1405 /* Select a new trial point.
1406 * If the derivatives at points a & c have different sign we interpolate to zero,
1407 * otherwise just do a bisection.
1409 if (gpa < 0 && gpc > 0)
1411 b = a + gpa*(a-c)/(gpc-gpa);
1418 /* safeguard if interpolation close to machine accuracy causes errors:
1419 * never go outside the interval
1421 if (b <= a || b >= c)
1426 if (DOMAINDECOMP(cr) && s_min->s.ddp_count != cr->dd->ddp_count)
1428 /* Reload the old state */
1429 em_dd_partition_system(fplog, mdlog, -1, cr, top_global, inputrec,
1430 s_min, top, mdAtoms, fr, vsite, constr,
1434 /* Take a trial step to this new point - new coords in s_b */
1435 do_em_step(cr, inputrec, mdatoms, s_min, b, &s_min->s.cg_p, s_b,
1439 /* Calculate energy for the trial step */
1440 energyEvaluator.run(s_b, mu_tot, vir, pres, -1, FALSE);
1442 /* p does not change within a step, but since the domain decomposition
1443 * might change, we have to use cg_p of s_b here.
1445 const rvec *pb = as_rvec_array(s_b->s.cg_p.data());
1446 const rvec *sfb = as_rvec_array(s_b->f.data());
1448 for (int i = 0; i < mdatoms->homenr; i++)
1450 for (m = 0; m < DIM; m++)
1452 gpb -= pb[i][m]*sfb[i][m]; /* f is negative gradient, thus the sign */
1455 /* Sum the gradient along the line across CPUs */
1458 gmx_sumd(1, &gpb, cr);
1463 fprintf(debug, "CGE: EpotA %f EpotB %f EpotC %f gpb %f\n",
1464 s_a->epot, s_b->epot, s_c->epot, gpb);
1467 epot_repl = s_b->epot;
1469 /* Keep one of the intervals based on the value of the derivative at the new point */
1472 /* Replace c endpoint with b */
1473 swap_em_state(&s_b, &s_c);
1479 /* Replace a endpoint with b */
1480 swap_em_state(&s_b, &s_a);
1486 * Stop search as soon as we find a value smaller than the endpoints.
1487 * Never run more than 20 steps, no matter what.
1491 while ((epot_repl > s_a->epot || epot_repl > s_c->epot) &&
1494 if (std::fabs(epot_repl - s_min->epot) < fabs(s_min->epot)*GMX_REAL_EPS ||
1497 /* OK. We couldn't find a significantly lower energy.
1498 * If beta==0 this was steepest descent, and then we give up.
1499 * If not, set beta=0 and restart with steepest descent before quitting.
1509 /* Reset memory before giving up */
1515 /* Select min energy state of A & C, put the best in B.
1517 if (s_c->epot < s_a->epot)
1521 fprintf(debug, "CGE: C (%f) is lower than A (%f), moving C to B\n",
1522 s_c->epot, s_a->epot);
1524 swap_em_state(&s_b, &s_c);
1531 fprintf(debug, "CGE: A (%f) is lower than C (%f), moving A to B\n",
1532 s_a->epot, s_c->epot);
1534 swap_em_state(&s_b, &s_a);
1543 fprintf(debug, "CGE: Found a lower energy %f, moving C to B\n",
1546 swap_em_state(&s_b, &s_c);
1550 /* new search direction */
1551 /* beta = 0 means forget all memory and restart with steepest descents. */
1552 if (nstcg && ((step % nstcg) == 0))
1558 /* s_min->fnorm cannot be zero, because then we would have converged
1562 /* Polak-Ribiere update.
1563 * Change to fnorm2/fnorm2_old for Fletcher-Reeves
1565 beta = pr_beta(cr, &inputrec->opts, mdatoms, top_global, s_min, s_b);
1567 /* Limit beta to prevent oscillations */
1568 if (fabs(beta) > 5.0)
1574 /* update positions */
1575 swap_em_state(&s_min, &s_b);
1578 /* Print it if necessary */
1581 if (mdrunOptions.verbose)
1583 double sqrtNumAtoms = sqrt(static_cast<double>(state_global->natoms));
1584 fprintf(stderr, "\rStep %d, Epot=%12.6e, Fnorm=%9.3e, Fmax=%9.3e (atom %d)\n",
1585 step, s_min->epot, s_min->fnorm/sqrtNumAtoms,
1586 s_min->fmax, s_min->a_fmax+1);
1589 /* Store the new (lower) energies */
1590 upd_mdebin(mdebin, FALSE, FALSE, static_cast<double>(step),
1591 mdatoms->tmass, enerd, &s_min->s, inputrec->fepvals, inputrec->expandedvals, s_min->s.box,
1592 nullptr, nullptr, vir, pres, nullptr, mu_tot, constr);
1594 do_log = do_per_step(step, inputrec->nstlog);
1595 do_ene = do_per_step(step, inputrec->nstenergy);
1597 /* Prepare IMD energy record, if bIMD is TRUE. */
1598 IMD_fill_energy_record(inputrec->bIMD, inputrec->imd, enerd, step, TRUE);
1602 print_ebin_header(fplog, step, step);
1604 print_ebin(mdoutf_get_fp_ene(outf), do_ene, FALSE, FALSE,
1605 do_log ? fplog : nullptr, step, step, eprNORMAL,
1606 mdebin, fcd, &(top_global->groups), &(inputrec->opts), nullptr);
1609 /* Send energies and positions to the IMD client if bIMD is TRUE. */
1610 if (MASTER(cr) && do_IMD(inputrec->bIMD, step, cr, TRUE, state_global->box, as_rvec_array(state_global->x.data()), inputrec, 0, wcycle))
1612 IMD_send_positions(inputrec->imd);
1615 /* Stop when the maximum force lies below tolerance.
1616 * If we have reached machine precision, converged is already set to true.
1618 converged = converged || (s_min->fmax < inputrec->em_tol);
1620 } /* End of the loop */
1622 /* IMD cleanup, if bIMD is TRUE. */
1623 IMD_finalize(inputrec->bIMD, inputrec->imd);
1627 step--; /* we never took that last step in this case */
1630 if (s_min->fmax > inputrec->em_tol)
1634 warn_step(fplog, inputrec->em_tol, s_min->fmax,
1635 step-1 == number_steps, FALSE);
1642 /* If we printed energy and/or logfile last step (which was the last step)
1643 * we don't have to do it again, but otherwise print the final values.
1647 /* Write final value to log since we didn't do anything the last step */
1648 print_ebin_header(fplog, step, step);
1650 if (!do_ene || !do_log)
1652 /* Write final energy file entries */
1653 print_ebin(mdoutf_get_fp_ene(outf), !do_ene, FALSE, FALSE,
1654 !do_log ? fplog : nullptr, step, step, eprNORMAL,
1655 mdebin, fcd, &(top_global->groups), &(inputrec->opts), nullptr);
1659 /* Print some stuff... */
1662 fprintf(stderr, "\nwriting lowest energy coordinates.\n");
1666 * For accurate normal mode calculation it is imperative that we
1667 * store the last conformation into the full precision binary trajectory.
1669 * However, we should only do it if we did NOT already write this step
1670 * above (which we did if do_x or do_f was true).
1672 /* Note that with 0 < nstfout != nstxout we can end up with two frames
1673 * in the trajectory with the same step number.
1675 do_x = !do_per_step(step, inputrec->nstxout);
1676 do_f = (inputrec->nstfout > 0 && !do_per_step(step, inputrec->nstfout));
1678 write_em_traj(fplog, cr, outf, do_x, do_f, ftp2fn(efSTO, nfile, fnm),
1679 top_global, inputrec, step,
1680 s_min, state_global, observablesHistory);
1685 double sqrtNumAtoms = sqrt(static_cast<double>(state_global->natoms));
1686 print_converged(stderr, CG, inputrec->em_tol, step, converged, number_steps,
1687 s_min, sqrtNumAtoms);
1688 print_converged(fplog, CG, inputrec->em_tol, step, converged, number_steps,
1689 s_min, sqrtNumAtoms);
1691 fprintf(fplog, "\nPerformed %d energy evaluations in total.\n", neval);
1694 finish_em(cr, outf, walltime_accounting, wcycle);
1696 /* To print the actual number of steps we needed somewhere */
1697 walltime_accounting_set_nsteps_done(walltime_accounting, step);
1702 Integrator::do_lbfgs()
1704 static const char *LBFGS = "Low-Memory BFGS Minimizer";
1706 gmx_localtop_t *top;
1707 gmx_enerdata_t *enerd;
1708 gmx_global_stat_t gstat;
1710 int ncorr, nmaxcorr, point, cp, neval, nminstep;
1711 double stepsize, step_taken, gpa, gpb, gpc, tmp, minstep;
1712 real *rho, *alpha, *p, *s, **dx, **dg;
1713 real a, b, c, maxdelta, delta;
1715 real dgdx, dgdg, sq, yr, beta;
1719 gmx_bool do_log, do_ene, do_x, do_f, foundlower, *frozen;
1721 int start, end, number_steps;
1723 int i, k, m, n, gf, step;
1725 auto mdatoms = mdAtoms->mdatoms();
1729 gmx_fatal(FARGS, "Cannot do parallel L-BFGS Minimization - yet.\n");
1732 if (nullptr != constr)
1734 gmx_fatal(FARGS, "The combination of constraints and L-BFGS minimization is not implemented. Either do not use constraints, or use another minimizer (e.g. steepest descent).");
1737 n = 3*state_global->natoms;
1738 nmaxcorr = inputrec->nbfgscorr;
1743 snew(rho, nmaxcorr);
1744 snew(alpha, nmaxcorr);
1747 for (i = 0; i < nmaxcorr; i++)
1753 for (i = 0; i < nmaxcorr; i++)
1762 init_em(fplog, mdlog, LBFGS, cr, ms, outputProvider, inputrec, mdrunOptions,
1763 state_global, top_global, &ems, &top,
1764 nrnb, mu_tot, fr, &enerd, &graph, mdAtoms, &gstat,
1765 vsite, constr, nullptr,
1766 nfile, fnm, &outf, &mdebin, wcycle);
1769 end = mdatoms->homenr;
1771 /* We need 4 working states */
1772 em_state_t s0 {}, s1 {}, s2 {}, s3 {};
1773 em_state_t *sa = &s0;
1774 em_state_t *sb = &s1;
1775 em_state_t *sc = &s2;
1776 em_state_t *last = &s3;
1777 /* Initialize by copying the state from ems (we could skip x and f here) */
1782 /* Print to log file */
1783 print_em_start(fplog, cr, walltime_accounting, wcycle, LBFGS);
1785 do_log = do_ene = do_x = do_f = TRUE;
1787 /* Max number of steps */
1788 number_steps = inputrec->nsteps;
1790 /* Create a 3*natoms index to tell whether each degree of freedom is frozen */
1792 for (i = start; i < end; i++)
1794 if (mdatoms->cFREEZE)
1796 gf = mdatoms->cFREEZE[i];
1798 for (m = 0; m < DIM; m++)
1800 frozen[3*i+m] = (inputrec->opts.nFreeze[gf][m] != 0);
1805 sp_header(stderr, LBFGS, inputrec->em_tol, number_steps);
1809 sp_header(fplog, LBFGS, inputrec->em_tol, number_steps);
1814 construct_vsites(vsite, as_rvec_array(state_global->x.data()), 1, nullptr,
1815 top->idef.iparams, top->idef.il,
1816 fr->ePBC, fr->bMolPBC, cr, state_global->box);
1819 /* Call the force routine and some auxiliary (neighboursearching etc.) */
1820 /* do_force always puts the charge groups in the box and shifts again
1821 * We do not unshift, so molecules are always whole
1824 EnergyEvaluator energyEvaluator {
1825 fplog, mdlog, cr, ms,
1827 inputrec, nrnb, wcycle, gstat,
1828 vsite, constr, fcd, graph,
1831 energyEvaluator.run(&ems, mu_tot, vir, pres, -1, TRUE);
1835 /* Copy stuff to the energy bin for easy printing etc. */
1836 upd_mdebin(mdebin, FALSE, FALSE, static_cast<double>(step),
1837 mdatoms->tmass, enerd, state_global, inputrec->fepvals, inputrec->expandedvals, state_global->box,
1838 nullptr, nullptr, vir, pres, nullptr, mu_tot, constr);
1840 print_ebin_header(fplog, step, step);
1841 print_ebin(mdoutf_get_fp_ene(outf), TRUE, FALSE, FALSE, fplog, step, step, eprNORMAL,
1842 mdebin, fcd, &(top_global->groups), &(inputrec->opts), nullptr);
1845 /* Set the initial step.
1846 * since it will be multiplied by the non-normalized search direction
1847 * vector (force vector the first time), we scale it by the
1848 * norm of the force.
1853 double sqrtNumAtoms = sqrt(static_cast<double>(state_global->natoms));
1854 fprintf(stderr, "Using %d BFGS correction steps.\n\n", nmaxcorr);
1855 fprintf(stderr, " F-max = %12.5e on atom %d\n", ems.fmax, ems.a_fmax + 1);
1856 fprintf(stderr, " F-Norm = %12.5e\n", ems.fnorm/sqrtNumAtoms);
1857 fprintf(stderr, "\n");
1858 /* and copy to the log file too... */
1859 fprintf(fplog, "Using %d BFGS correction steps.\n\n", nmaxcorr);
1860 fprintf(fplog, " F-max = %12.5e on atom %d\n", ems.fmax, ems.a_fmax + 1);
1861 fprintf(fplog, " F-Norm = %12.5e\n", ems.fnorm/sqrtNumAtoms);
1862 fprintf(fplog, "\n");
1865 // Point is an index to the memory of search directions, where 0 is the first one.
1868 // Set initial search direction to the force (-gradient), or 0 for frozen particles.
1869 real *fInit = static_cast<real *>(as_rvec_array(ems.f.data())[0]);
1870 for (i = 0; i < n; i++)
1874 dx[point][i] = fInit[i]; /* Initial search direction */
1882 // Stepsize will be modified during the search, and actually it is not critical
1883 // (the main efficiency in the algorithm comes from changing directions), but
1884 // we still need an initial value, so estimate it as the inverse of the norm
1885 // so we take small steps where the potential fluctuates a lot.
1886 stepsize = 1.0/ems.fnorm;
1888 /* Start the loop over BFGS steps.
1889 * Each successful step is counted, and we continue until
1890 * we either converge or reach the max number of steps.
1895 /* Set the gradient from the force */
1897 for (step = 0; (number_steps < 0 || step <= number_steps) && !converged; step++)
1900 /* Write coordinates if necessary */
1901 do_x = do_per_step(step, inputrec->nstxout);
1902 do_f = do_per_step(step, inputrec->nstfout);
1907 mdof_flags |= MDOF_X;
1912 mdof_flags |= MDOF_F;
1917 mdof_flags |= MDOF_IMD;
1920 mdoutf_write_to_trajectory_files(fplog, cr, outf, mdof_flags,
1921 top_global, step, static_cast<real>(step), &ems.s, state_global, observablesHistory, ems.f);
1923 /* Do the linesearching in the direction dx[point][0..(n-1)] */
1925 /* make s a pointer to current search direction - point=0 first time we get here */
1928 real *xx = static_cast<real *>(as_rvec_array(ems.s.x.data())[0]);
1929 real *ff = static_cast<real *>(as_rvec_array(ems.f.data())[0]);
1931 // calculate line gradient in position A
1932 for (gpa = 0, i = 0; i < n; i++)
1937 /* Calculate minimum allowed stepsize along the line, before the average (norm)
1938 * relative change in coordinate is smaller than precision
1940 for (minstep = 0, i = 0; i < n; i++)
1950 minstep = GMX_REAL_EPS/sqrt(minstep/n);
1952 if (stepsize < minstep)
1958 // Before taking any steps along the line, store the old position
1960 real *lastx = static_cast<real *>(as_rvec_array(last->s.x.data())[0]);
1961 real *lastf = static_cast<real *>(as_rvec_array(last->f.data())[0]);
1966 /* Take a step downhill.
1967 * In theory, we should find the actual minimum of the function in this
1968 * direction, somewhere along the line.
1969 * That is quite possible, but it turns out to take 5-10 function evaluations
1970 * for each line. However, we dont really need to find the exact minimum -
1971 * it is much better to start a new BFGS step in a modified direction as soon
1972 * as we are close to it. This will save a lot of energy evaluations.
1974 * In practice, we just try to take a single step.
1975 * If it worked (i.e. lowered the energy), we increase the stepsize but
1976 * continue straight to the next BFGS step without trying to find any minimum,
1977 * i.e. we change the search direction too. If the line was smooth, it is
1978 * likely we are in a smooth region, and then it makes sense to take longer
1979 * steps in the modified search direction too.
1981 * If it didn't work (higher energy), there must be a minimum somewhere between
1982 * the old position and the new one. Then we need to start by finding a lower
1983 * value before we change search direction. Since the energy was apparently
1984 * quite rough, we need to decrease the step size.
1986 * Due to the finite numerical accuracy, it turns out that it is a good idea
1987 * to accept a SMALL increase in energy, if the derivative is still downhill.
1988 * This leads to lower final energies in the tests I've done. / Erik
1991 // State "A" is the first position along the line.
1992 // reference position along line is initially zero
1995 // Check stepsize first. We do not allow displacements
1996 // larger than emstep.
2000 // Pick a new position C by adding stepsize to A.
2003 // Calculate what the largest change in any individual coordinate
2004 // would be (translation along line * gradient along line)
2006 for (i = 0; i < n; i++)
2009 if (delta > maxdelta)
2014 // If any displacement is larger than the stepsize limit, reduce the step
2015 if (maxdelta > inputrec->em_stepsize)
2020 while (maxdelta > inputrec->em_stepsize);
2022 // Take a trial step and move the coordinate array xc[] to position C
2023 real *xc = static_cast<real *>(as_rvec_array(sc->s.x.data())[0]);
2024 for (i = 0; i < n; i++)
2026 xc[i] = lastx[i] + c*s[i];
2030 // Calculate energy for the trial step in position C
2031 energyEvaluator.run(sc, mu_tot, vir, pres, step, FALSE);
2033 // Calc line gradient in position C
2034 real *fc = static_cast<real *>(as_rvec_array(sc->f.data())[0]);
2035 for (gpc = 0, i = 0; i < n; i++)
2037 gpc -= s[i]*fc[i]; /* f is negative gradient, thus the sign */
2039 /* Sum the gradient along the line across CPUs */
2042 gmx_sumd(1, &gpc, cr);
2045 // This is the max amount of increase in energy we tolerate.
2046 // By allowing VERY small changes (close to numerical precision) we
2047 // frequently find even better (lower) final energies.
2048 tmp = std::sqrt(GMX_REAL_EPS)*fabs(sa->epot);
2050 // Accept the step if the energy is lower in the new position C (compared to A),
2051 // or if it is not significantly higher and the line derivative is still negative.
2052 foundlower = sc->epot < sa->epot || (gpc < 0 && sc->epot < (sa->epot + tmp));
2053 // If true, great, we found a better energy. We no longer try to alter the
2054 // stepsize, but simply accept this new better position. The we select a new
2055 // search direction instead, which will be much more efficient than continuing
2056 // to take smaller steps along a line. Set fnorm based on the new C position,
2057 // which will be used to update the stepsize to 1/fnorm further down.
2059 // If false, the energy is NOT lower in point C, i.e. it will be the same
2060 // or higher than in point A. In this case it is pointless to move to point C,
2061 // so we will have to do more iterations along the same line to find a smaller
2062 // value in the interval [A=0.0,C].
2063 // Here, A is still 0.0, but that will change when we do a search in the interval
2064 // [0.0,C] below. That search we will do by interpolation or bisection rather
2065 // than with the stepsize, so no need to modify it. For the next search direction
2066 // it will be reset to 1/fnorm anyway.
2070 // OK, if we didn't find a lower value we will have to locate one now - there must
2071 // be one in the interval [a,c].
2072 // The same thing is valid here, though: Don't spend dozens of iterations to find
2073 // the line minimum. We try to interpolate based on the derivative at the endpoints,
2074 // and only continue until we find a lower value. In most cases this means 1-2 iterations.
2075 // I also have a safeguard for potentially really pathological functions so we never
2076 // take more than 20 steps before we give up.
2077 // If we already found a lower value we just skip this step and continue to the update.
2082 // Select a new trial point B in the interval [A,C].
2083 // If the derivatives at points a & c have different sign we interpolate to zero,
2084 // otherwise just do a bisection since there might be multiple minima/maxima
2085 // inside the interval.
2086 if (gpa < 0 && gpc > 0)
2088 b = a + gpa*(a-c)/(gpc-gpa);
2095 /* safeguard if interpolation close to machine accuracy causes errors:
2096 * never go outside the interval
2098 if (b <= a || b >= c)
2103 // Take a trial step to point B
2104 real *xb = static_cast<real *>(as_rvec_array(sb->s.x.data())[0]);
2105 for (i = 0; i < n; i++)
2107 xb[i] = lastx[i] + b*s[i];
2111 // Calculate energy for the trial step in point B
2112 energyEvaluator.run(sb, mu_tot, vir, pres, step, FALSE);
2115 // Calculate gradient in point B
2116 real *fb = static_cast<real *>(as_rvec_array(sb->f.data())[0]);
2117 for (gpb = 0, i = 0; i < n; i++)
2119 gpb -= s[i]*fb[i]; /* f is negative gradient, thus the sign */
2122 /* Sum the gradient along the line across CPUs */
2125 gmx_sumd(1, &gpb, cr);
2128 // Keep one of the intervals [A,B] or [B,C] based on the value of the derivative
2129 // at the new point B, and rename the endpoints of this new interval A and C.
2132 /* Replace c endpoint with b */
2134 /* swap states b and c */
2135 swap_em_state(&sb, &sc);
2139 /* Replace a endpoint with b */
2141 /* swap states a and b */
2142 swap_em_state(&sa, &sb);
2146 * Stop search as soon as we find a value smaller than the endpoints,
2147 * or if the tolerance is below machine precision.
2148 * Never run more than 20 steps, no matter what.
2152 while ((sb->epot > sa->epot || sb->epot > sc->epot) && (nminstep < 20));
2154 if (std::fabs(sb->epot - Epot0) < GMX_REAL_EPS || nminstep >= 20)
2156 /* OK. We couldn't find a significantly lower energy.
2157 * If ncorr==0 this was steepest descent, and then we give up.
2158 * If not, reset memory to restart as steepest descent before quitting.
2170 /* Search in gradient direction */
2171 for (i = 0; i < n; i++)
2173 dx[point][i] = ff[i];
2175 /* Reset stepsize */
2176 stepsize = 1.0/fnorm;
2181 /* Select min energy state of A & C, put the best in xx/ff/Epot
2183 if (sc->epot < sa->epot)
2205 /* Update the memory information, and calculate a new
2206 * approximation of the inverse hessian
2209 /* Have new data in Epot, xx, ff */
2210 if (ncorr < nmaxcorr)
2215 for (i = 0; i < n; i++)
2217 dg[point][i] = lastf[i]-ff[i];
2218 dx[point][i] *= step_taken;
2223 for (i = 0; i < n; i++)
2225 dgdg += dg[point][i]*dg[point][i];
2226 dgdx += dg[point][i]*dx[point][i];
2231 rho[point] = 1.0/dgdx;
2234 if (point >= nmaxcorr)
2240 for (i = 0; i < n; i++)
2247 /* Recursive update. First go back over the memory points */
2248 for (k = 0; k < ncorr; k++)
2257 for (i = 0; i < n; i++)
2259 sq += dx[cp][i]*p[i];
2262 alpha[cp] = rho[cp]*sq;
2264 for (i = 0; i < n; i++)
2266 p[i] -= alpha[cp]*dg[cp][i];
2270 for (i = 0; i < n; i++)
2275 /* And then go forward again */
2276 for (k = 0; k < ncorr; k++)
2279 for (i = 0; i < n; i++)
2281 yr += p[i]*dg[cp][i];
2285 beta = alpha[cp]-beta;
2287 for (i = 0; i < n; i++)
2289 p[i] += beta*dx[cp][i];
2299 for (i = 0; i < n; i++)
2303 dx[point][i] = p[i];
2311 /* Print it if necessary */
2314 if (mdrunOptions.verbose)
2316 double sqrtNumAtoms = sqrt(static_cast<double>(state_global->natoms));
2317 fprintf(stderr, "\rStep %d, Epot=%12.6e, Fnorm=%9.3e, Fmax=%9.3e (atom %d)\n",
2318 step, ems.epot, ems.fnorm/sqrtNumAtoms, ems.fmax, ems.a_fmax + 1);
2321 /* Store the new (lower) energies */
2322 upd_mdebin(mdebin, FALSE, FALSE, static_cast<double>(step),
2323 mdatoms->tmass, enerd, state_global, inputrec->fepvals, inputrec->expandedvals, state_global->box,
2324 nullptr, nullptr, vir, pres, nullptr, mu_tot, constr);
2325 do_log = do_per_step(step, inputrec->nstlog);
2326 do_ene = do_per_step(step, inputrec->nstenergy);
2329 print_ebin_header(fplog, step, step);
2331 print_ebin(mdoutf_get_fp_ene(outf), do_ene, FALSE, FALSE,
2332 do_log ? fplog : nullptr, step, step, eprNORMAL,
2333 mdebin, fcd, &(top_global->groups), &(inputrec->opts), nullptr);
2336 /* Send x and E to IMD client, if bIMD is TRUE. */
2337 if (do_IMD(inputrec->bIMD, step, cr, TRUE, state_global->box, as_rvec_array(state_global->x.data()), inputrec, 0, wcycle) && MASTER(cr))
2339 IMD_send_positions(inputrec->imd);
2342 // Reset stepsize in we are doing more iterations
2343 stepsize = 1.0/ems.fnorm;
2345 /* Stop when the maximum force lies below tolerance.
2346 * If we have reached machine precision, converged is already set to true.
2348 converged = converged || (ems.fmax < inputrec->em_tol);
2350 } /* End of the loop */
2352 /* IMD cleanup, if bIMD is TRUE. */
2353 IMD_finalize(inputrec->bIMD, inputrec->imd);
2357 step--; /* we never took that last step in this case */
2360 if (ems.fmax > inputrec->em_tol)
2364 warn_step(fplog, inputrec->em_tol, ems.fmax,
2365 step-1 == number_steps, FALSE);
2370 /* If we printed energy and/or logfile last step (which was the last step)
2371 * we don't have to do it again, but otherwise print the final values.
2373 if (!do_log) /* Write final value to log since we didn't do anythin last step */
2375 print_ebin_header(fplog, step, step);
2377 if (!do_ene || !do_log) /* Write final energy file entries */
2379 print_ebin(mdoutf_get_fp_ene(outf), !do_ene, FALSE, FALSE,
2380 !do_log ? fplog : nullptr, step, step, eprNORMAL,
2381 mdebin, fcd, &(top_global->groups), &(inputrec->opts), nullptr);
2384 /* Print some stuff... */
2387 fprintf(stderr, "\nwriting lowest energy coordinates.\n");
2391 * For accurate normal mode calculation it is imperative that we
2392 * store the last conformation into the full precision binary trajectory.
2394 * However, we should only do it if we did NOT already write this step
2395 * above (which we did if do_x or do_f was true).
2397 do_x = !do_per_step(step, inputrec->nstxout);
2398 do_f = !do_per_step(step, inputrec->nstfout);
2399 write_em_traj(fplog, cr, outf, do_x, do_f, ftp2fn(efSTO, nfile, fnm),
2400 top_global, inputrec, step,
2401 &ems, state_global, observablesHistory);
2405 double sqrtNumAtoms = sqrt(static_cast<double>(state_global->natoms));
2406 print_converged(stderr, LBFGS, inputrec->em_tol, step, converged,
2407 number_steps, &ems, sqrtNumAtoms);
2408 print_converged(fplog, LBFGS, inputrec->em_tol, step, converged,
2409 number_steps, &ems, sqrtNumAtoms);
2411 fprintf(fplog, "\nPerformed %d energy evaluations in total.\n", neval);
2414 finish_em(cr, outf, walltime_accounting, wcycle);
2416 /* To print the actual number of steps we needed somewhere */
2417 walltime_accounting_set_nsteps_done(walltime_accounting, step);
2421 Integrator::do_steep()
2423 const char *SD = "Steepest Descents";
2424 gmx_localtop_t *top;
2425 gmx_enerdata_t *enerd;
2426 gmx_global_stat_t gstat;
2432 gmx_bool bDone, bAbort, do_x, do_f;
2437 int steps_accepted = 0;
2438 auto mdatoms = mdAtoms->mdatoms();
2440 /* Create 2 states on the stack and extract pointers that we will swap */
2441 em_state_t s0 {}, s1 {};
2442 em_state_t *s_min = &s0;
2443 em_state_t *s_try = &s1;
2445 /* Init em and store the local state in s_try */
2446 init_em(fplog, mdlog, SD, cr, ms, outputProvider, inputrec, mdrunOptions,
2447 state_global, top_global, s_try, &top,
2448 nrnb, mu_tot, fr, &enerd, &graph, mdAtoms, &gstat,
2449 vsite, constr, nullptr,
2450 nfile, fnm, &outf, &mdebin, wcycle);
2452 /* Print to log file */
2453 print_em_start(fplog, cr, walltime_accounting, wcycle, SD);
2455 /* Set variables for stepsize (in nm). This is the largest
2456 * step that we are going to make in any direction.
2458 ustep = inputrec->em_stepsize;
2461 /* Max number of steps */
2462 nsteps = inputrec->nsteps;
2466 /* Print to the screen */
2467 sp_header(stderr, SD, inputrec->em_tol, nsteps);
2471 sp_header(fplog, SD, inputrec->em_tol, nsteps);
2473 EnergyEvaluator energyEvaluator {
2474 fplog, mdlog, cr, ms,
2476 inputrec, nrnb, wcycle, gstat,
2477 vsite, constr, fcd, graph,
2481 /**** HERE STARTS THE LOOP ****
2482 * count is the counter for the number of steps
2483 * bDone will be TRUE when the minimization has converged
2484 * bAbort will be TRUE when nsteps steps have been performed or when
2485 * the stepsize becomes smaller than is reasonable for machine precision
2490 while (!bDone && !bAbort)
2492 bAbort = (nsteps >= 0) && (count == nsteps);
2494 /* set new coordinates, except for first step */
2495 bool validStep = true;
2499 do_em_step(cr, inputrec, mdatoms,
2500 s_min, stepsize, &s_min->f, s_try,
2506 energyEvaluator.run(s_try, mu_tot, vir, pres, count, count == 0);
2510 // Signal constraint error during stepping with energy=inf
2511 s_try->epot = std::numeric_limits<real>::infinity();
2516 print_ebin_header(fplog, count, count);
2521 s_min->epot = s_try->epot;
2524 /* Print it if necessary */
2527 if (mdrunOptions.verbose)
2529 fprintf(stderr, "Step=%5d, Dmax= %6.1e nm, Epot= %12.5e Fmax= %11.5e, atom= %d%c",
2530 count, ustep, s_try->epot, s_try->fmax, s_try->a_fmax+1,
2531 ( (count == 0) || (s_try->epot < s_min->epot) ) ? '\n' : '\r');
2535 if ( (count == 0) || (s_try->epot < s_min->epot) )
2537 /* Store the new (lower) energies */
2538 upd_mdebin(mdebin, FALSE, FALSE, static_cast<double>(count),
2539 mdatoms->tmass, enerd, &s_try->s, inputrec->fepvals, inputrec->expandedvals,
2540 s_try->s.box, nullptr, nullptr, vir, pres, nullptr, mu_tot, constr);
2542 /* Prepare IMD energy record, if bIMD is TRUE. */
2543 IMD_fill_energy_record(inputrec->bIMD, inputrec->imd, enerd, count, TRUE);
2545 print_ebin(mdoutf_get_fp_ene(outf), TRUE,
2546 do_per_step(steps_accepted, inputrec->nstdisreout),
2547 do_per_step(steps_accepted, inputrec->nstorireout),
2548 fplog, count, count, eprNORMAL,
2549 mdebin, fcd, &(top_global->groups), &(inputrec->opts), nullptr);
2554 /* Now if the new energy is smaller than the previous...
2555 * or if this is the first step!
2556 * or if we did random steps!
2559 if ( (count == 0) || (s_try->epot < s_min->epot) )
2563 /* Test whether the convergence criterion is met... */
2564 bDone = (s_try->fmax < inputrec->em_tol);
2566 /* Copy the arrays for force, positions and energy */
2567 /* The 'Min' array always holds the coords and forces of the minimal
2569 swap_em_state(&s_min, &s_try);
2575 /* Write to trn, if necessary */
2576 do_x = do_per_step(steps_accepted, inputrec->nstxout);
2577 do_f = do_per_step(steps_accepted, inputrec->nstfout);
2578 write_em_traj(fplog, cr, outf, do_x, do_f, nullptr,
2579 top_global, inputrec, count,
2580 s_min, state_global, observablesHistory);
2584 /* If energy is not smaller make the step smaller... */
2587 if (DOMAINDECOMP(cr) && s_min->s.ddp_count != cr->dd->ddp_count)
2589 /* Reload the old state */
2590 em_dd_partition_system(fplog, mdlog, count, cr, top_global, inputrec,
2591 s_min, top, mdAtoms, fr, vsite, constr,
2596 /* Determine new step */
2597 stepsize = ustep/s_min->fmax;
2599 /* Check if stepsize is too small, with 1 nm as a characteristic length */
2601 if (count == nsteps || ustep < 1e-12)
2603 if (count == nsteps || ustep < 1e-6)
2608 warn_step(fplog, inputrec->em_tol, s_min->fmax,
2609 count == nsteps, constr != nullptr);
2614 /* Send IMD energies and positions, if bIMD is TRUE. */
2615 if (do_IMD(inputrec->bIMD, count, cr, TRUE, state_global->box,
2616 MASTER(cr) ? as_rvec_array(state_global->x.data()) : nullptr,
2617 inputrec, 0, wcycle) &&
2620 IMD_send_positions(inputrec->imd);
2624 } /* End of the loop */
2626 /* IMD cleanup, if bIMD is TRUE. */
2627 IMD_finalize(inputrec->bIMD, inputrec->imd);
2629 /* Print some data... */
2632 fprintf(stderr, "\nwriting lowest energy coordinates.\n");
2634 write_em_traj(fplog, cr, outf, TRUE, inputrec->nstfout != 0, ftp2fn(efSTO, nfile, fnm),
2635 top_global, inputrec, count,
2636 s_min, state_global, observablesHistory);
2640 double sqrtNumAtoms = sqrt(static_cast<double>(state_global->natoms));
2642 print_converged(stderr, SD, inputrec->em_tol, count, bDone, nsteps,
2643 s_min, sqrtNumAtoms);
2644 print_converged(fplog, SD, inputrec->em_tol, count, bDone, nsteps,
2645 s_min, sqrtNumAtoms);
2648 finish_em(cr, outf, walltime_accounting, wcycle);
2650 /* To print the actual number of steps we needed somewhere */
2651 inputrec->nsteps = count;
2653 walltime_accounting_set_nsteps_done(walltime_accounting, count);
2659 const char *NM = "Normal Mode Analysis";
2662 gmx_localtop_t *top;
2663 gmx_enerdata_t *enerd;
2664 gmx_global_stat_t gstat;
2669 gmx_bool bSparse; /* use sparse matrix storage format */
2671 gmx_sparsematrix_t * sparse_matrix = nullptr;
2672 real * full_matrix = nullptr;
2674 /* added with respect to mdrun */
2676 real der_range = 10.0*std::sqrt(GMX_REAL_EPS);
2678 bool bIsMaster = MASTER(cr);
2679 auto mdatoms = mdAtoms->mdatoms();
2681 if (constr != nullptr)
2683 gmx_fatal(FARGS, "Constraints present with Normal Mode Analysis, this combination is not supported");
2686 gmx_shellfc_t *shellfc;
2688 em_state_t state_work {};
2690 /* Init em and store the local state in state_minimum */
2691 init_em(fplog, mdlog, NM, cr, ms, outputProvider, inputrec, mdrunOptions,
2692 state_global, top_global, &state_work, &top,
2693 nrnb, mu_tot, fr, &enerd, &graph, mdAtoms, &gstat,
2694 vsite, constr, &shellfc,
2695 nfile, fnm, &outf, nullptr, wcycle);
2697 std::vector<int> atom_index = get_atom_index(top_global);
2698 snew(fneg, atom_index.size());
2699 snew(dfdx, atom_index.size());
2705 "NOTE: This version of GROMACS has been compiled in single precision,\n"
2706 " which MIGHT not be accurate enough for normal mode analysis.\n"
2707 " GROMACS now uses sparse matrix storage, so the memory requirements\n"
2708 " are fairly modest even if you recompile in double precision.\n\n");
2712 /* Check if we can/should use sparse storage format.
2714 * Sparse format is only useful when the Hessian itself is sparse, which it
2715 * will be when we use a cutoff.
2716 * For small systems (n<1000) it is easier to always use full matrix format, though.
2718 if (EEL_FULL(fr->ic->eeltype) || fr->rlist == 0.0)
2720 GMX_LOG(mdlog.warning).appendText("Non-cutoff electrostatics used, forcing full Hessian format.");
2723 else if (atom_index.size() < 1000)
2725 GMX_LOG(mdlog.warning).appendTextFormatted("Small system size (N=%zu), using full Hessian format.",
2731 GMX_LOG(mdlog.warning).appendText("Using compressed symmetric sparse Hessian format.");
2735 /* Number of dimensions, based on real atoms, that is not vsites or shell */
2736 sz = DIM*atom_index.size();
2738 fprintf(stderr, "Allocating Hessian memory...\n\n");
2742 sparse_matrix = gmx_sparsematrix_init(sz);
2743 sparse_matrix->compressed_symmetric = TRUE;
2747 snew(full_matrix, sz*sz);
2753 /* Write start time and temperature */
2754 print_em_start(fplog, cr, walltime_accounting, wcycle, NM);
2756 /* fudge nr of steps to nr of atoms */
2757 inputrec->nsteps = atom_index.size()*2;
2761 fprintf(stderr, "starting normal mode calculation '%s'\n%" PRId64 " steps.\n\n",
2762 *(top_global->name), inputrec->nsteps);
2765 nnodes = cr->nnodes;
2767 /* Make evaluate_energy do a single node force calculation */
2769 EnergyEvaluator energyEvaluator {
2770 fplog, mdlog, cr, ms,
2772 inputrec, nrnb, wcycle, gstat,
2773 vsite, constr, fcd, graph,
2776 energyEvaluator.run(&state_work, mu_tot, vir, pres, -1, TRUE);
2777 cr->nnodes = nnodes;
2779 /* if forces are not small, warn user */
2780 get_state_f_norm_max(cr, &(inputrec->opts), mdatoms, &state_work);
2782 GMX_LOG(mdlog.warning).appendTextFormatted("Maximum force:%12.5e", state_work.fmax);
2783 if (state_work.fmax > 1.0e-3)
2785 GMX_LOG(mdlog.warning).appendText(
2786 "The force is probably not small enough to "
2787 "ensure that you are at a minimum.\n"
2788 "Be aware that negative eigenvalues may occur\n"
2789 "when the resulting matrix is diagonalized.");
2792 /***********************************************************
2794 * Loop over all pairs in matrix
2796 * do_force called twice. Once with positive and
2797 * once with negative displacement
2799 ************************************************************/
2801 /* Steps are divided one by one over the nodes */
2803 for (unsigned int aid = cr->nodeid; aid < atom_index.size(); aid += nnodes)
2805 size_t atom = atom_index[aid];
2806 for (size_t d = 0; d < DIM; d++)
2809 int force_flags = GMX_FORCE_STATECHANGED | GMX_FORCE_ALLFORCES;
2812 x_min = state_work.s.x[atom][d];
2814 for (unsigned int dx = 0; (dx < 2); dx++)
2818 state_work.s.x[atom][d] = x_min - der_range;
2822 state_work.s.x[atom][d] = x_min + der_range;
2825 /* Make evaluate_energy do a single node force calculation */
2829 /* Now is the time to relax the shells */
2830 relax_shell_flexcon(fplog,
2833 mdrunOptions.verbose,
2850 &top_global->groups,
2856 DdOpenBalanceRegionBeforeForceComputation::no,
2857 DdCloseBalanceRegionAfterForceComputation::no);
2863 energyEvaluator.run(&state_work, mu_tot, vir, pres, atom*2+dx, FALSE);
2866 cr->nnodes = nnodes;
2870 for (size_t i = 0; i < atom_index.size(); i++)
2872 copy_rvec(state_work.f[atom_index[i]], fneg[i]);
2877 /* x is restored to original */
2878 state_work.s.x[atom][d] = x_min;
2880 for (size_t j = 0; j < atom_index.size(); j++)
2882 for (size_t k = 0; (k < DIM); k++)
2885 -(state_work.f[atom_index[j]][k] - fneg[j][k])/(2*der_range);
2892 #define mpi_type GMX_MPI_REAL
2893 MPI_Send(dfdx[0], atom_index.size()*DIM, mpi_type, MASTER(cr),
2894 cr->nodeid, cr->mpi_comm_mygroup);
2899 for (node = 0; (node < nnodes && atom+node < atom_index.size()); node++)
2905 MPI_Recv(dfdx[0], atom_index.size()*DIM, mpi_type, node, node,
2906 cr->mpi_comm_mygroup, &stat);
2911 row = (atom + node)*DIM + d;
2913 for (size_t j = 0; j < atom_index.size(); j++)
2915 for (size_t k = 0; k < DIM; k++)
2921 if (col >= row && dfdx[j][k] != 0.0)
2923 gmx_sparsematrix_increment_value(sparse_matrix,
2924 row, col, dfdx[j][k]);
2929 full_matrix[row*sz+col] = dfdx[j][k];
2936 if (mdrunOptions.verbose && fplog)
2941 /* write progress */
2942 if (bIsMaster && mdrunOptions.verbose)
2944 fprintf(stderr, "\rFinished step %d out of %d",
2945 static_cast<int>(std::min(atom+nnodes, atom_index.size())),
2946 static_cast<int>(atom_index.size()));
2953 fprintf(stderr, "\n\nWriting Hessian...\n");
2954 gmx_mtxio_write(ftp2fn(efMTX, nfile, fnm), sz, sz, full_matrix, sparse_matrix);
2957 finish_em(cr, outf, walltime_accounting, wcycle);
2959 walltime_accounting_set_nsteps_done(walltime_accounting, atom_index.size()*2);