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38 /* This file is completely threadsafe - keep it that way! */
43 #include "gromacs/math/functions.h"
44 #include "gromacs/math/invertmatrix.h"
45 #include "gromacs/math/vec.h"
46 #include "gromacs/math/vecdump.h"
47 #include "gromacs/mdlib/gmx_omp_nthreads.h"
48 #include "gromacs/mdtypes/inputrec.h"
49 #include "gromacs/mdtypes/md_enums.h"
50 #include "gromacs/pbcutil/pbc.h"
51 #include "gromacs/topology/topology.h"
52 #include "gromacs/utility/fatalerror.h"
53 #include "gromacs/utility/gmxassert.h"
54 #include "gromacs/utility/gmxomp.h"
55 #include "gromacs/utility/smalloc.h"
57 t_vcm::t_vcm(const SimulationGroups& groups, const t_inputrec& ir) :
58 integratorConservesMomentum(!EI_RANDOM(ir.eI))
60 mode = (ir.nstcomm > 0) ? ir.comm_mode : ecmNO;
62 timeStep = ir.nstcomm * ir.delta_t;
64 if (mode == ecmANGULAR && ndim < 3)
66 gmx_fatal(FARGS, "Can not have angular comm removal with pbc=%s",
67 c_pbcTypeNames[ir.pbcType].c_str());
72 nr = groups.groups[SimulationAtomGroupType::MassCenterVelocityRemoval].size();
73 /* Allocate one extra for a possible rest group */
75 /* We need vcm->nr+1 elements per thread, but to avoid cache
76 * invalidation we add 2 elements to get a 152 byte separation.
79 if (mode == ecmANGULAR)
88 group_name.resize(size);
91 group_mass.resize(size);
92 group_ndf.resize(size);
93 for (int g = 0; (g < nr); g++)
95 group_ndf[g] = ir.opts.nrdf[g];
97 *groups.groupNames[groups.groups[SimulationAtomGroupType::MassCenterVelocityRemoval][g]];
100 thread_vcm.resize(gmx_omp_nthreads_get(emntDefault) * stride);
103 nFreeze = ir.opts.nFreeze;
108 if (mode == ecmANGULAR)
114 void reportComRemovalInfo(FILE* fp, const t_vcm& vcm)
117 /* Copy pointer to group names and print it. */
118 if (fp && vcm.mode != ecmNO)
120 fprintf(fp, "Center of mass motion removal mode is %s\n", ECOM(vcm.mode));
122 "We have the following groups for center of"
123 " mass motion removal:\n");
125 for (int g = 0; (g < vcm.nr); g++)
128 fprintf(fp, "%3d: %s\n", g, vcm.group_name[g]);
134 static void update_tensor(const rvec x, real m0, tensor I)
138 /* Compute inertia tensor contribution due to this atom */
139 xy = x[XX] * x[YY] * m0;
140 xz = x[XX] * x[ZZ] * m0;
141 yz = x[YY] * x[ZZ] * m0;
142 I[XX][XX] += x[XX] * x[XX] * m0;
143 I[YY][YY] += x[YY] * x[YY] * m0;
144 I[ZZ][ZZ] += x[ZZ] * x[ZZ] * m0;
153 /* Center of mass code for groups */
154 void calc_vcm_grp(const t_mdatoms& md, const rvec x[], const rvec v[], t_vcm* vcm)
156 if (vcm->mode == ecmNO)
160 int nthreads = gmx_omp_nthreads_get(emntDefault);
163 #pragma omp parallel num_threads(nthreads) default(none) shared(x, v, vcm, md)
165 int t = gmx_omp_get_thread_num();
166 for (int g = 0; g < vcm->size; g++)
168 /* Reset linear momentum */
169 t_vcm_thread* vcm_t = &vcm->thread_vcm[t * vcm->stride + g];
171 clear_rvec(vcm_t->p);
172 if (vcm->mode == ecmANGULAR)
174 /* Reset angular momentum */
175 clear_rvec(vcm_t->j);
176 clear_rvec(vcm_t->x);
181 #pragma omp for schedule(static)
182 for (int i = 0; i < md.homenr; i++)
185 real m0 = md.massT[i];
190 t_vcm_thread* vcm_t = &vcm->thread_vcm[t * vcm->stride + g];
191 /* Calculate linear momentum */
194 for (m = 0; (m < DIM); m++)
196 vcm_t->p[m] += m0 * v[i][m];
199 if (vcm->mode == ecmANGULAR)
201 /* Calculate angular momentum */
203 cprod(x[i], v[i], j0);
205 for (m = 0; (m < DIM); m++)
207 vcm_t->j[m] += m0 * j0[m];
208 vcm_t->x[m] += m0 * x[i][m];
210 /* Update inertia tensor */
211 update_tensor(x[i], m0, vcm_t->i);
215 for (int g = 0; g < vcm->size; g++)
217 /* Reset linear momentum */
218 vcm->group_mass[g] = 0;
219 clear_rvec(vcm->group_p[g]);
220 if (vcm->mode == ecmANGULAR)
222 /* Reset angular momentum */
223 clear_rvec(vcm->group_j[g]);
224 clear_rvec(vcm->group_x[g]);
225 clear_rvec(vcm->group_w[g]);
226 clear_mat(vcm->group_i[g]);
229 for (int t = 0; t < nthreads; t++)
231 t_vcm_thread* vcm_t = &vcm->thread_vcm[t * vcm->stride + g];
232 vcm->group_mass[g] += vcm_t->mass;
233 rvec_inc(vcm->group_p[g], vcm_t->p);
234 if (vcm->mode == ecmANGULAR)
236 rvec_inc(vcm->group_j[g], vcm_t->j);
237 rvec_inc(vcm->group_x[g], vcm_t->x);
238 m_add(vcm_t->i, vcm->group_i[g], vcm->group_i[g]);
245 /*! \brief Remove the COM motion velocity from the velocities
247 * \note This routine should be called from within an OpenMP parallel region.
249 * \tparam numDimensions Correct dimensions 0 to \p numDimensions-1
250 * \param[in] mdatoms The atom property and group information
251 * \param[in,out] v The velocities to correct
252 * \param[in] vcm VCM data
254 template<int numDimensions>
255 static void doStopComMotionLinear(const t_mdatoms& mdatoms, rvec* v, const t_vcm& vcm)
257 const int homenr = mdatoms.homenr;
258 const unsigned short* group_id = mdatoms.cVCM;
260 if (mdatoms.cFREEZE != nullptr)
262 GMX_RELEASE_ASSERT(vcm.nFreeze != nullptr, "Need freeze dimension info with freeze groups");
264 #pragma omp for schedule(static)
265 for (int i = 0; i < homenr; i++)
267 unsigned short vcmGroup = (group_id == nullptr ? 0 : group_id[i]);
268 unsigned short freezeGroup = mdatoms.cFREEZE[i];
269 for (int d = 0; d < numDimensions; d++)
271 if (vcm.nFreeze[freezeGroup][d] == 0)
273 v[i][d] -= vcm.group_v[vcmGroup][d];
278 else if (group_id == nullptr)
280 #pragma omp for schedule(static)
281 for (int i = 0; i < homenr; i++)
283 for (int d = 0; d < numDimensions; d++)
285 v[i][d] -= vcm.group_v[0][d];
291 #pragma omp for schedule(static)
292 for (int i = 0; i < homenr; i++)
294 const int g = group_id[i];
295 for (int d = 0; d < numDimensions; d++)
297 v[i][d] -= vcm.group_v[g][d];
303 /*! \brief Remove the COM motion velocity from the velocities, correct the coordinates assuming constant acceleration
305 * \note This routine should be called from within an OpenMP parallel region.
307 * \tparam numDimensions Correct dimensions 0 to \p numDimensions-1
308 * \param[in] homenr The number of atoms to correct
309 * \param[in] group_id List of VCM group ids, when nullptr is passed all atoms are assumed to be in group 0
310 * \param[in,out] x The coordinates to correct
311 * \param[in,out] v The velocities to correct
312 * \param[in] vcm VCM data
314 template<int numDimensions>
315 static void doStopComMotionAccelerationCorrection(int homenr,
316 const unsigned short* group_id,
317 rvec* gmx_restrict x,
318 rvec* gmx_restrict v,
321 const real xCorrectionFactor = 0.5 * vcm.timeStep;
323 if (group_id == nullptr)
325 #pragma omp for schedule(static)
326 for (int i = 0; i < homenr; i++)
328 for (int d = 0; d < numDimensions; d++)
330 x[i][d] -= vcm.group_v[0][d] * xCorrectionFactor;
331 v[i][d] -= vcm.group_v[0][d];
337 #pragma omp for schedule(static)
338 for (int i = 0; i < homenr; i++)
340 const int g = group_id[i];
341 for (int d = 0; d < numDimensions; d++)
343 x[i][d] -= vcm.group_v[g][d] * xCorrectionFactor;
344 v[i][d] -= vcm.group_v[g][d];
350 static void do_stopcm_grp(const t_mdatoms& mdatoms, rvec x[], rvec v[], const t_vcm& vcm)
352 if (vcm.mode == ecmNO)
357 const int homenr = mdatoms.homenr;
358 const unsigned short* group_id = mdatoms.cVCM;
360 int gmx_unused nth = gmx_omp_nthreads_get(emntDefault);
361 // homenr could be shared, but gcc-8 & gcc-9 don't agree how to write that...
362 // https://www.gnu.org/software/gcc/gcc-9/porting_to.html -> OpenMP data sharing
363 #pragma omp parallel num_threads(nth) default(none) shared(x, v, vcm, group_id, mdatoms) \
366 if (vcm.mode == ecmLINEAR || vcm.mode == ecmANGULAR
367 || (vcm.mode == ecmLINEAR_ACCELERATION_CORRECTION && x == nullptr))
369 /* Subtract linear momentum for v */
372 case 1: doStopComMotionLinear<1>(mdatoms, v, vcm); break;
373 case 2: doStopComMotionLinear<2>(mdatoms, v, vcm); break;
374 case 3: doStopComMotionLinear<3>(mdatoms, v, vcm); break;
379 GMX_ASSERT(vcm.mode == ecmLINEAR_ACCELERATION_CORRECTION,
380 "When the mode is not linear or angular, it should be acceleration "
382 /* Subtract linear momentum for v and x*/
386 doStopComMotionAccelerationCorrection<1>(homenr, group_id, x, v, vcm);
389 doStopComMotionAccelerationCorrection<2>(homenr, group_id, x, v, vcm);
392 doStopComMotionAccelerationCorrection<3>(homenr, group_id, x, v, vcm);
396 if (vcm.mode == ecmANGULAR)
398 /* Subtract angular momentum */
399 GMX_ASSERT(x, "Need x to compute angular momentum correction");
402 #pragma omp for schedule(static)
403 for (int i = 0; i < homenr; i++)
409 /* Compute the correction to the velocity for each atom */
411 rvec_sub(x[i], vcm.group_x[g], dx);
412 cprod(vcm.group_w[g], dx, dv);
420 static void get_minv(tensor A, tensor B)
426 tmp[XX][XX] = A[YY][YY] + A[ZZ][ZZ];
427 tmp[YY][XX] = -A[XX][YY];
428 tmp[ZZ][XX] = -A[XX][ZZ];
429 tmp[XX][YY] = -A[XX][YY];
430 tmp[YY][YY] = A[XX][XX] + A[ZZ][ZZ];
431 tmp[ZZ][YY] = -A[YY][ZZ];
432 tmp[XX][ZZ] = -A[XX][ZZ];
433 tmp[YY][ZZ] = -A[YY][ZZ];
434 tmp[ZZ][ZZ] = A[XX][XX] + A[YY][YY];
436 /* This is a hack to prevent very large determinants */
437 rfac = (tmp[XX][XX] + tmp[YY][YY] + tmp[ZZ][ZZ]) / 3;
440 gmx_fatal(FARGS, "Can not stop center of mass: maybe 2dimensional system");
443 for (m = 0; (m < DIM); m++)
445 for (n = 0; (n < DIM); n++)
450 gmx::invertMatrix(tmp, B);
451 for (m = 0; (m < DIM); m++)
453 for (n = 0; (n < DIM); n++)
460 /* Processes VCM after reduction over ranks and prints warning with high VMC and fp != nullptr */
461 static void process_and_check_cm_grp(FILE* fp, t_vcm* vcm, real Temp_Max)
464 real ekcm, ekrot, tm, tm_1, Temp_cm;
468 /* First analyse the total results */
469 if (vcm->mode != ecmNO)
471 for (g = 0; (g < vcm->nr); g++)
473 tm = vcm->group_mass[g];
477 svmul(tm_1, vcm->group_p[g], vcm->group_v[g]);
479 /* Else it's zero anyway! */
481 if (vcm->mode == ecmANGULAR)
483 for (g = 0; (g < vcm->nr); g++)
485 tm = vcm->group_mass[g];
490 /* Compute center of mass for this group */
491 for (m = 0; (m < DIM); m++)
493 vcm->group_x[g][m] *= tm_1;
496 /* Subtract the center of mass contribution to the
499 cprod(vcm->group_x[g], vcm->group_v[g], jcm);
500 for (m = 0; (m < DIM); m++)
502 vcm->group_j[g][m] -= tm * jcm[m];
505 /* Subtract the center of mass contribution from the inertia
506 * tensor (this is not as trivial as it seems, but due to
507 * some cancellation we can still do it, even in parallel).
510 update_tensor(vcm->group_x[g], tm, Icm);
511 m_sub(vcm->group_i[g], Icm, vcm->group_i[g]);
513 /* Compute angular velocity, using matrix operation
518 get_minv(vcm->group_i[g], Icm);
519 mvmul(Icm, vcm->group_j[g], vcm->group_w[g]);
521 /* Else it's zero anyway! */
525 for (g = 0; (g < vcm->nr); g++)
528 if (vcm->group_mass[g] != 0 && vcm->group_ndf[g] > 0)
530 for (m = 0; m < vcm->ndim; m++)
532 ekcm += gmx::square(vcm->group_v[g][m]);
534 ekcm *= 0.5 * vcm->group_mass[g];
535 Temp_cm = 2 * ekcm / vcm->group_ndf[g];
537 if ((Temp_cm > Temp_Max) && fp)
539 fprintf(fp, "Large VCM(group %s): %12.5f, %12.5f, %12.5f, Temp-cm: %12.5e\n",
540 vcm->group_name[g], vcm->group_v[g][XX], vcm->group_v[g][YY],
541 vcm->group_v[g][ZZ], Temp_cm);
544 if (vcm->mode == ecmANGULAR)
546 ekrot = 0.5 * iprod(vcm->group_j[g], vcm->group_w[g]);
547 // TODO: Change absolute energy comparison to relative
548 if ((ekrot > 1) && fp && vcm->integratorConservesMomentum)
550 /* if we have an integrator that may not conserve momenta, skip */
551 tm = vcm->group_mass[g];
552 fprintf(fp, "Group %s with mass %12.5e, Ekrot %12.5e Det(I) = %12.5e\n",
553 vcm->group_name[g], tm, ekrot, det(vcm->group_i[g]));
554 fprintf(fp, " COM: %12.5f %12.5f %12.5f\n", vcm->group_x[g][XX],
555 vcm->group_x[g][YY], vcm->group_x[g][ZZ]);
556 fprintf(fp, " P: %12.5f %12.5f %12.5f\n", vcm->group_p[g][XX],
557 vcm->group_p[g][YY], vcm->group_p[g][ZZ]);
558 fprintf(fp, " V: %12.5f %12.5f %12.5f\n", vcm->group_v[g][XX],
559 vcm->group_v[g][YY], vcm->group_v[g][ZZ]);
560 fprintf(fp, " J: %12.5f %12.5f %12.5f\n", vcm->group_j[g][XX],
561 vcm->group_j[g][YY], vcm->group_j[g][ZZ]);
562 fprintf(fp, " w: %12.5f %12.5f %12.5f\n", vcm->group_w[g][XX],
563 vcm->group_w[g][YY], vcm->group_w[g][ZZ]);
564 pr_rvecs(fp, 0, "Inertia tensor", vcm->group_i[g], DIM);
571 void process_and_stopcm_grp(FILE* fplog, t_vcm* vcm, const t_mdatoms& mdatoms, rvec x[], rvec v[])
573 if (vcm->mode != ecmNO)
575 // TODO: Replace fixed temperature of 1 by a system value
576 process_and_check_cm_grp(fplog, vcm, 1);
578 do_stopcm_grp(mdatoms, x, v, *vcm);