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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/mdtypes/mdatom.h"
51 #include "gromacs/pbcutil/pbc.h"
52 #include "gromacs/topology/topology.h"
53 #include "gromacs/utility/fatalerror.h"
54 #include "gromacs/utility/gmxassert.h"
55 #include "gromacs/utility/gmxomp.h"
56 #include "gromacs/utility/smalloc.h"
58 t_vcm::t_vcm(const SimulationGroups& groups, const t_inputrec& ir) :
59 integratorConservesMomentum(!EI_RANDOM(ir.eI))
61 mode = (ir.nstcomm > 0) ? ir.comm_mode : ecmNO;
63 timeStep = ir.nstcomm * ir.delta_t;
65 if (mode == ecmANGULAR && ndim < 3)
67 gmx_fatal(FARGS, "Can not have angular comm removal with pbc=%s",
68 c_pbcTypeNames[ir.pbcType].c_str());
73 nr = groups.groups[SimulationAtomGroupType::MassCenterVelocityRemoval].size();
74 /* Allocate one extra for a possible rest group */
76 /* We need vcm->nr+1 elements per thread, but to avoid cache
77 * invalidation we add 2 elements to get a 152 byte separation.
80 if (mode == ecmANGULAR)
89 group_name.resize(size);
92 group_mass.resize(size);
93 group_ndf.resize(size);
94 for (int g = 0; (g < nr); g++)
96 group_ndf[g] = ir.opts.nrdf[g];
98 *groups.groupNames[groups.groups[SimulationAtomGroupType::MassCenterVelocityRemoval][g]];
101 thread_vcm.resize(gmx_omp_nthreads_get(emntDefault) * stride);
104 nFreeze = ir.opts.nFreeze;
109 if (mode == ecmANGULAR)
115 void reportComRemovalInfo(FILE* fp, const t_vcm& vcm)
118 /* Copy pointer to group names and print it. */
119 if (fp && vcm.mode != ecmNO)
121 fprintf(fp, "Center of mass motion removal mode is %s\n", ECOM(vcm.mode));
123 "We have the following groups for center of"
124 " mass motion removal:\n");
126 for (int g = 0; (g < vcm.nr); g++)
129 fprintf(fp, "%3d: %s\n", g, vcm.group_name[g]);
135 static void update_tensor(const rvec x, real m0, tensor I)
139 /* Compute inertia tensor contribution due to this atom */
140 xy = x[XX] * x[YY] * m0;
141 xz = x[XX] * x[ZZ] * m0;
142 yz = x[YY] * x[ZZ] * m0;
143 I[XX][XX] += x[XX] * x[XX] * m0;
144 I[YY][YY] += x[YY] * x[YY] * m0;
145 I[ZZ][ZZ] += x[ZZ] * x[ZZ] * m0;
154 /* Center of mass code for groups */
155 void calc_vcm_grp(const t_mdatoms& md, const rvec x[], const rvec v[], t_vcm* vcm)
157 if (vcm->mode == ecmNO)
161 int nthreads = gmx_omp_nthreads_get(emntDefault);
164 #pragma omp parallel num_threads(nthreads) default(none) shared(x, v, vcm, md)
166 int t = gmx_omp_get_thread_num();
167 for (int g = 0; g < vcm->size; g++)
169 /* Reset linear momentum */
170 t_vcm_thread* vcm_t = &vcm->thread_vcm[t * vcm->stride + g];
172 clear_rvec(vcm_t->p);
173 if (vcm->mode == ecmANGULAR)
175 /* Reset angular momentum */
176 clear_rvec(vcm_t->j);
177 clear_rvec(vcm_t->x);
182 #pragma omp for schedule(static)
183 for (int i = 0; i < md.homenr; i++)
186 real m0 = md.massT[i];
191 t_vcm_thread* vcm_t = &vcm->thread_vcm[t * vcm->stride + g];
192 /* Calculate linear momentum */
195 for (m = 0; (m < DIM); m++)
197 vcm_t->p[m] += m0 * v[i][m];
200 if (vcm->mode == ecmANGULAR)
202 /* Calculate angular momentum */
204 cprod(x[i], v[i], j0);
206 for (m = 0; (m < DIM); m++)
208 vcm_t->j[m] += m0 * j0[m];
209 vcm_t->x[m] += m0 * x[i][m];
211 /* Update inertia tensor */
212 update_tensor(x[i], m0, vcm_t->i);
216 for (int g = 0; g < vcm->size; g++)
218 /* Reset linear momentum */
219 vcm->group_mass[g] = 0;
220 clear_rvec(vcm->group_p[g]);
221 if (vcm->mode == ecmANGULAR)
223 /* Reset angular momentum */
224 clear_rvec(vcm->group_j[g]);
225 clear_rvec(vcm->group_x[g]);
226 clear_rvec(vcm->group_w[g]);
227 clear_mat(vcm->group_i[g]);
230 for (int t = 0; t < nthreads; t++)
232 t_vcm_thread* vcm_t = &vcm->thread_vcm[t * vcm->stride + g];
233 vcm->group_mass[g] += vcm_t->mass;
234 rvec_inc(vcm->group_p[g], vcm_t->p);
235 if (vcm->mode == ecmANGULAR)
237 rvec_inc(vcm->group_j[g], vcm_t->j);
238 rvec_inc(vcm->group_x[g], vcm_t->x);
239 m_add(vcm_t->i, vcm->group_i[g], vcm->group_i[g]);
246 /*! \brief Remove the COM motion velocity from the velocities
248 * \note This routine should be called from within an OpenMP parallel region.
250 * \tparam numDimensions Correct dimensions 0 to \p numDimensions-1
251 * \param[in] mdatoms The atom property and group information
252 * \param[in,out] v The velocities to correct
253 * \param[in] vcm VCM data
255 template<int numDimensions>
256 static void doStopComMotionLinear(const t_mdatoms& mdatoms, rvec* v, const t_vcm& vcm)
258 const int homenr = mdatoms.homenr;
259 const unsigned short* group_id = mdatoms.cVCM;
261 if (mdatoms.cFREEZE != nullptr)
263 GMX_RELEASE_ASSERT(vcm.nFreeze != nullptr, "Need freeze dimension info with freeze groups");
265 #pragma omp for schedule(static)
266 for (int i = 0; i < homenr; i++)
268 unsigned short vcmGroup = (group_id == nullptr ? 0 : group_id[i]);
269 unsigned short freezeGroup = mdatoms.cFREEZE[i];
270 for (int d = 0; d < numDimensions; d++)
272 if (vcm.nFreeze[freezeGroup][d] == 0)
274 v[i][d] -= vcm.group_v[vcmGroup][d];
279 else if (group_id == nullptr)
281 #pragma omp for schedule(static)
282 for (int i = 0; i < homenr; i++)
284 for (int d = 0; d < numDimensions; d++)
286 v[i][d] -= vcm.group_v[0][d];
292 #pragma omp for schedule(static)
293 for (int i = 0; i < homenr; i++)
295 const int g = group_id[i];
296 for (int d = 0; d < numDimensions; d++)
298 v[i][d] -= vcm.group_v[g][d];
304 /*! \brief Remove the COM motion velocity from the velocities, correct the coordinates assuming constant acceleration
306 * \note This routine should be called from within an OpenMP parallel region.
308 * \tparam numDimensions Correct dimensions 0 to \p numDimensions-1
309 * \param[in] homenr The number of atoms to correct
310 * \param[in] group_id List of VCM group ids, when nullptr is passed all atoms are assumed to be in group 0
311 * \param[in,out] x The coordinates to correct
312 * \param[in,out] v The velocities to correct
313 * \param[in] vcm VCM data
315 template<int numDimensions>
316 static void doStopComMotionAccelerationCorrection(int homenr,
317 const unsigned short* group_id,
318 rvec* gmx_restrict x,
319 rvec* gmx_restrict v,
322 const real xCorrectionFactor = 0.5 * vcm.timeStep;
324 if (group_id == nullptr)
326 #pragma omp for schedule(static)
327 for (int i = 0; i < homenr; i++)
329 for (int d = 0; d < numDimensions; d++)
331 x[i][d] -= vcm.group_v[0][d] * xCorrectionFactor;
332 v[i][d] -= vcm.group_v[0][d];
338 #pragma omp for schedule(static)
339 for (int i = 0; i < homenr; i++)
341 const int g = group_id[i];
342 for (int d = 0; d < numDimensions; d++)
344 x[i][d] -= vcm.group_v[g][d] * xCorrectionFactor;
345 v[i][d] -= vcm.group_v[g][d];
351 static void do_stopcm_grp(const t_mdatoms& mdatoms, rvec x[], rvec v[], const t_vcm& vcm)
353 if (vcm.mode == ecmNO)
358 const int homenr = mdatoms.homenr;
359 const unsigned short* group_id = mdatoms.cVCM;
361 int gmx_unused nth = gmx_omp_nthreads_get(emntDefault);
362 // homenr could be shared, but gcc-8 & gcc-9 don't agree how to write that...
363 // https://www.gnu.org/software/gcc/gcc-9/porting_to.html -> OpenMP data sharing
364 #pragma omp parallel num_threads(nth) default(none) shared(x, v, vcm, group_id, mdatoms) \
367 if (vcm.mode == ecmLINEAR || vcm.mode == ecmANGULAR
368 || (vcm.mode == ecmLINEAR_ACCELERATION_CORRECTION && x == nullptr))
370 /* Subtract linear momentum for v */
373 case 1: doStopComMotionLinear<1>(mdatoms, v, vcm); break;
374 case 2: doStopComMotionLinear<2>(mdatoms, v, vcm); break;
375 case 3: doStopComMotionLinear<3>(mdatoms, v, vcm); break;
380 GMX_ASSERT(vcm.mode == ecmLINEAR_ACCELERATION_CORRECTION,
381 "When the mode is not linear or angular, it should be acceleration "
383 /* Subtract linear momentum for v and x*/
387 doStopComMotionAccelerationCorrection<1>(homenr, group_id, x, v, vcm);
390 doStopComMotionAccelerationCorrection<2>(homenr, group_id, x, v, vcm);
393 doStopComMotionAccelerationCorrection<3>(homenr, group_id, x, v, vcm);
397 if (vcm.mode == ecmANGULAR)
399 /* Subtract angular momentum */
400 GMX_ASSERT(x, "Need x to compute angular momentum correction");
403 #pragma omp for schedule(static)
404 for (int i = 0; i < homenr; i++)
410 /* Compute the correction to the velocity for each atom */
412 rvec_sub(x[i], vcm.group_x[g], dx);
413 cprod(vcm.group_w[g], dx, dv);
421 static void get_minv(tensor A, tensor B)
427 tmp[XX][XX] = A[YY][YY] + A[ZZ][ZZ];
428 tmp[YY][XX] = -A[XX][YY];
429 tmp[ZZ][XX] = -A[XX][ZZ];
430 tmp[XX][YY] = -A[XX][YY];
431 tmp[YY][YY] = A[XX][XX] + A[ZZ][ZZ];
432 tmp[ZZ][YY] = -A[YY][ZZ];
433 tmp[XX][ZZ] = -A[XX][ZZ];
434 tmp[YY][ZZ] = -A[YY][ZZ];
435 tmp[ZZ][ZZ] = A[XX][XX] + A[YY][YY];
437 /* This is a hack to prevent very large determinants */
438 rfac = (tmp[XX][XX] + tmp[YY][YY] + tmp[ZZ][ZZ]) / 3;
441 gmx_fatal(FARGS, "Can not stop center of mass: maybe 2dimensional system");
444 for (m = 0; (m < DIM); m++)
446 for (n = 0; (n < DIM); n++)
451 gmx::invertMatrix(tmp, B);
452 for (m = 0; (m < DIM); m++)
454 for (n = 0; (n < DIM); n++)
461 /* Processes VCM after reduction over ranks and prints warning with high VMC and fp != nullptr */
462 static void process_and_check_cm_grp(FILE* fp, t_vcm* vcm, real Temp_Max)
465 real ekcm, ekrot, tm, tm_1, Temp_cm;
469 /* First analyse the total results */
470 if (vcm->mode != ecmNO)
472 for (g = 0; (g < vcm->nr); g++)
474 tm = vcm->group_mass[g];
478 svmul(tm_1, vcm->group_p[g], vcm->group_v[g]);
480 /* Else it's zero anyway! */
482 if (vcm->mode == ecmANGULAR)
484 for (g = 0; (g < vcm->nr); g++)
486 tm = vcm->group_mass[g];
491 /* Compute center of mass for this group */
492 for (m = 0; (m < DIM); m++)
494 vcm->group_x[g][m] *= tm_1;
497 /* Subtract the center of mass contribution to the
500 cprod(vcm->group_x[g], vcm->group_v[g], jcm);
501 for (m = 0; (m < DIM); m++)
503 vcm->group_j[g][m] -= tm * jcm[m];
506 /* Subtract the center of mass contribution from the inertia
507 * tensor (this is not as trivial as it seems, but due to
508 * some cancellation we can still do it, even in parallel).
511 update_tensor(vcm->group_x[g], tm, Icm);
512 m_sub(vcm->group_i[g], Icm, vcm->group_i[g]);
514 /* Compute angular velocity, using matrix operation
519 get_minv(vcm->group_i[g], Icm);
520 mvmul(Icm, vcm->group_j[g], vcm->group_w[g]);
522 /* Else it's zero anyway! */
526 for (g = 0; (g < vcm->nr); g++)
529 if (vcm->group_mass[g] != 0 && vcm->group_ndf[g] > 0)
531 for (m = 0; m < vcm->ndim; m++)
533 ekcm += gmx::square(vcm->group_v[g][m]);
535 ekcm *= 0.5 * vcm->group_mass[g];
536 Temp_cm = 2 * ekcm / vcm->group_ndf[g];
538 if ((Temp_cm > Temp_Max) && fp)
540 fprintf(fp, "Large VCM(group %s): %12.5f, %12.5f, %12.5f, Temp-cm: %12.5e\n",
541 vcm->group_name[g], vcm->group_v[g][XX], vcm->group_v[g][YY],
542 vcm->group_v[g][ZZ], Temp_cm);
545 if (vcm->mode == ecmANGULAR)
547 ekrot = 0.5 * iprod(vcm->group_j[g], vcm->group_w[g]);
548 // TODO: Change absolute energy comparison to relative
549 if ((ekrot > 1) && fp && vcm->integratorConservesMomentum)
551 /* if we have an integrator that may not conserve momenta, skip */
552 tm = vcm->group_mass[g];
553 fprintf(fp, "Group %s with mass %12.5e, Ekrot %12.5e Det(I) = %12.5e\n",
554 vcm->group_name[g], tm, ekrot, det(vcm->group_i[g]));
555 fprintf(fp, " COM: %12.5f %12.5f %12.5f\n", vcm->group_x[g][XX],
556 vcm->group_x[g][YY], vcm->group_x[g][ZZ]);
557 fprintf(fp, " P: %12.5f %12.5f %12.5f\n", vcm->group_p[g][XX],
558 vcm->group_p[g][YY], vcm->group_p[g][ZZ]);
559 fprintf(fp, " V: %12.5f %12.5f %12.5f\n", vcm->group_v[g][XX],
560 vcm->group_v[g][YY], vcm->group_v[g][ZZ]);
561 fprintf(fp, " J: %12.5f %12.5f %12.5f\n", vcm->group_j[g][XX],
562 vcm->group_j[g][YY], vcm->group_j[g][ZZ]);
563 fprintf(fp, " w: %12.5f %12.5f %12.5f\n", vcm->group_w[g][XX],
564 vcm->group_w[g][YY], vcm->group_w[g][ZZ]);
565 pr_rvecs(fp, 0, "Inertia tensor", vcm->group_i[g], DIM);
572 void process_and_stopcm_grp(FILE* fplog, t_vcm* vcm, const t_mdatoms& mdatoms, rvec x[], rvec v[])
574 if (vcm->mode != ecmNO)
576 // TODO: Replace fixed temperature of 1 by a system value
577 process_and_check_cm_grp(fplog, vcm, 1);
579 do_stopcm_grp(mdatoms, x, v, *vcm);