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37 /* This file is completely threadsafe - keep it that way! */
42 #include "gromacs/gmxlib/network.h"
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", epbc_names[ir.ePBC]);
71 nr = groups.groups[SimulationAtomGroupType::MassCenterVelocityRemoval].size();
72 /* Allocate one extra for a possible rest group */
74 /* We need vcm->nr+1 elements per thread, but to avoid cache
75 * invalidation we add 2 elements to get a 152 byte separation.
78 if (mode == ecmANGULAR)
87 group_name.resize(size);
90 group_mass.resize(size);
91 group_ndf.resize(size);
92 for (int g = 0; (g < nr); g++)
94 group_ndf[g] = ir.opts.nrdf[g];
96 *groups.groupNames[groups.groups[SimulationAtomGroupType::MassCenterVelocityRemoval][g]];
99 thread_vcm.resize(gmx_omp_nthreads_get(emntDefault) * stride);
102 nFreeze = ir.opts.nFreeze;
107 if (mode == ecmANGULAR)
113 void reportComRemovalInfo(FILE* fp, const t_vcm& vcm)
116 /* Copy pointer to group names and print it. */
117 if (fp && vcm.mode != ecmNO)
119 fprintf(fp, "Center of mass motion removal mode is %s\n", ECOM(vcm.mode));
121 "We have the following groups for center of"
122 " mass motion removal:\n");
124 for (int g = 0; (g < vcm.nr); g++)
127 fprintf(fp, "%3d: %s\n", g, vcm.group_name[g]);
133 static void update_tensor(const rvec x, real m0, tensor I)
137 /* Compute inertia tensor contribution due to this atom */
138 xy = x[XX] * x[YY] * m0;
139 xz = x[XX] * x[ZZ] * m0;
140 yz = x[YY] * x[ZZ] * m0;
141 I[XX][XX] += x[XX] * x[XX] * m0;
142 I[YY][YY] += x[YY] * x[YY] * m0;
143 I[ZZ][ZZ] += x[ZZ] * x[ZZ] * m0;
152 /* Center of mass code for groups */
153 void calc_vcm_grp(const t_mdatoms& md, const rvec x[], const rvec v[], t_vcm* vcm)
155 int nthreads = gmx_omp_nthreads_get(emntDefault);
156 if (vcm->mode != ecmNO)
158 #pragma omp parallel num_threads(nthreads)
160 int t = gmx_omp_get_thread_num();
161 for (int g = 0; g < vcm->size; g++)
163 /* Reset linear momentum */
164 t_vcm_thread* vcm_t = &vcm->thread_vcm[t * vcm->stride + g];
166 clear_rvec(vcm_t->p);
167 if (vcm->mode == ecmANGULAR)
169 /* Reset angular momentum */
170 clear_rvec(vcm_t->j);
171 clear_rvec(vcm_t->x);
176 #pragma omp for schedule(static)
177 for (int i = 0; i < md.homenr; i++)
180 real m0 = md.massT[i];
185 t_vcm_thread* vcm_t = &vcm->thread_vcm[t * vcm->stride + g];
186 /* Calculate linear momentum */
189 for (m = 0; (m < DIM); m++)
191 vcm_t->p[m] += m0 * v[i][m];
194 if (vcm->mode == ecmANGULAR)
196 /* Calculate angular momentum */
198 cprod(x[i], v[i], j0);
200 for (m = 0; (m < DIM); m++)
202 vcm_t->j[m] += m0 * j0[m];
203 vcm_t->x[m] += m0 * x[i][m];
205 /* Update inertia tensor */
206 update_tensor(x[i], m0, vcm_t->i);
210 for (int g = 0; g < vcm->size; g++)
212 /* Reset linear momentum */
213 vcm->group_mass[g] = 0;
214 clear_rvec(vcm->group_p[g]);
215 if (vcm->mode == ecmANGULAR)
217 /* Reset angular momentum */
218 clear_rvec(vcm->group_j[g]);
219 clear_rvec(vcm->group_x[g]);
220 clear_rvec(vcm->group_w[g]);
221 clear_mat(vcm->group_i[g]);
224 for (int t = 0; t < nthreads; t++)
226 t_vcm_thread* vcm_t = &vcm->thread_vcm[t * vcm->stride + g];
227 vcm->group_mass[g] += vcm_t->mass;
228 rvec_inc(vcm->group_p[g], vcm_t->p);
229 if (vcm->mode == ecmANGULAR)
231 rvec_inc(vcm->group_j[g], vcm_t->j);
232 rvec_inc(vcm->group_x[g], vcm_t->x);
233 m_add(vcm_t->i, vcm->group_i[g], vcm->group_i[g]);
240 /*! \brief Remove the COM motion velocity from the velocities
242 * \note This routine should be called from within an OpenMP parallel region.
244 * \tparam numDimensions Correct dimensions 0 to \p numDimensions-1
245 * \param[in] mdatoms The atom property and group information
246 * \param[in,out] v The velocities to correct
247 * \param[in] vcm VCM data
249 template<int numDimensions>
250 static void doStopComMotionLinear(const t_mdatoms& mdatoms, rvec* v, const t_vcm& vcm)
252 const int homenr = mdatoms.homenr;
253 const unsigned short* group_id = mdatoms.cVCM;
255 if (mdatoms.cFREEZE != nullptr)
257 GMX_RELEASE_ASSERT(vcm.nFreeze != nullptr, "Need freeze dimension info with freeze groups");
259 #pragma omp for schedule(static)
260 for (int i = 0; i < homenr; i++)
262 unsigned short vcmGroup = (group_id == nullptr ? 0 : group_id[i]);
263 unsigned short freezeGroup = mdatoms.cFREEZE[i];
264 for (int d = 0; d < numDimensions; d++)
266 if (vcm.nFreeze[freezeGroup][d] == 0)
268 v[i][d] -= vcm.group_v[vcmGroup][d];
273 else if (group_id == nullptr)
275 #pragma omp for schedule(static)
276 for (int i = 0; i < homenr; i++)
278 for (int d = 0; d < numDimensions; d++)
280 v[i][d] -= vcm.group_v[0][d];
286 #pragma omp for schedule(static)
287 for (int i = 0; i < homenr; i++)
289 const int g = group_id[i];
290 for (int d = 0; d < numDimensions; d++)
292 v[i][d] -= vcm.group_v[g][d];
298 /*! \brief Remove the COM motion velocity from the velocities, correct the coordinates assuming constant acceleration
300 * \note This routine should be called from within an OpenMP parallel region.
302 * \tparam numDimensions Correct dimensions 0 to \p numDimensions-1
303 * \param[in] homenr The number of atoms to correct
304 * \param[in] group_id List of VCM group ids, when nullptr is passed all atoms are assumed to be in group 0
305 * \param[in,out] x The coordinates to correct
306 * \param[in,out] v The velocities to correct
307 * \param[in] vcm VCM data
309 template<int numDimensions>
310 static void doStopComMotionAccelerationCorrection(int homenr,
311 const unsigned short* group_id,
312 rvec* gmx_restrict x,
313 rvec* gmx_restrict v,
316 const real xCorrectionFactor = 0.5 * vcm.timeStep;
318 if (group_id == nullptr)
320 #pragma omp for schedule(static)
321 for (int i = 0; i < homenr; i++)
323 for (int d = 0; d < numDimensions; d++)
325 x[i][d] -= vcm.group_v[0][d] * xCorrectionFactor;
326 v[i][d] -= vcm.group_v[0][d];
332 #pragma omp for schedule(static)
333 for (int i = 0; i < homenr; i++)
335 const int g = group_id[i];
336 for (int d = 0; d < numDimensions; d++)
338 x[i][d] -= vcm.group_v[g][d] * xCorrectionFactor;
339 v[i][d] -= vcm.group_v[g][d];
345 static void do_stopcm_grp(const t_mdatoms& mdatoms, rvec x[], rvec v[], const t_vcm& vcm)
347 if (vcm.mode != ecmNO)
349 const int homenr = mdatoms.homenr;
350 const unsigned short* group_id = mdatoms.cVCM;
352 int gmx_unused nth = gmx_omp_nthreads_get(emntDefault);
353 #pragma omp parallel num_threads(nth)
355 if (vcm.mode == ecmLINEAR || vcm.mode == ecmANGULAR
356 || (vcm.mode == ecmLINEAR_ACCELERATION_CORRECTION && x == nullptr))
358 /* Subtract linear momentum for v */
361 case 1: doStopComMotionLinear<1>(mdatoms, v, vcm); break;
362 case 2: doStopComMotionLinear<2>(mdatoms, v, vcm); break;
363 case 3: doStopComMotionLinear<3>(mdatoms, v, vcm); break;
368 GMX_ASSERT(vcm.mode == ecmLINEAR_ACCELERATION_CORRECTION,
369 "When the mode is not linear or angular, it should be acceleration "
371 /* Subtract linear momentum for v and x*/
375 doStopComMotionAccelerationCorrection<1>(homenr, group_id, x, v, vcm);
378 doStopComMotionAccelerationCorrection<2>(homenr, group_id, x, v, vcm);
381 doStopComMotionAccelerationCorrection<3>(homenr, group_id, x, v, vcm);
385 if (vcm.mode == ecmANGULAR)
387 /* Subtract angular momentum */
388 GMX_ASSERT(x, "Need x to compute angular momentum correction");
391 #pragma omp for schedule(static)
392 for (int i = 0; i < homenr; i++)
398 /* Compute the correction to the velocity for each atom */
400 rvec_sub(x[i], vcm.group_x[g], dx);
401 cprod(vcm.group_w[g], dx, dv);
409 static void get_minv(tensor A, tensor B)
415 tmp[XX][XX] = A[YY][YY] + A[ZZ][ZZ];
416 tmp[YY][XX] = -A[XX][YY];
417 tmp[ZZ][XX] = -A[XX][ZZ];
418 tmp[XX][YY] = -A[XX][YY];
419 tmp[YY][YY] = A[XX][XX] + A[ZZ][ZZ];
420 tmp[ZZ][YY] = -A[YY][ZZ];
421 tmp[XX][ZZ] = -A[XX][ZZ];
422 tmp[YY][ZZ] = -A[YY][ZZ];
423 tmp[ZZ][ZZ] = A[XX][XX] + A[YY][YY];
425 /* This is a hack to prevent very large determinants */
426 rfac = (tmp[XX][XX] + tmp[YY][YY] + tmp[ZZ][ZZ]) / 3;
429 gmx_fatal(FARGS, "Can not stop center of mass: maybe 2dimensional system");
432 for (m = 0; (m < DIM); m++)
434 for (n = 0; (n < DIM); n++)
439 gmx::invertMatrix(tmp, B);
440 for (m = 0; (m < DIM); m++)
442 for (n = 0; (n < DIM); n++)
449 /* Processes VCM after reduction over ranks and prints warning with high VMC and fp != nullptr */
450 static void process_and_check_cm_grp(FILE* fp, t_vcm* vcm, real Temp_Max)
453 real ekcm, ekrot, tm, tm_1, Temp_cm;
457 /* First analyse the total results */
458 if (vcm->mode != ecmNO)
460 for (g = 0; (g < vcm->nr); g++)
462 tm = vcm->group_mass[g];
466 svmul(tm_1, vcm->group_p[g], vcm->group_v[g]);
468 /* Else it's zero anyway! */
470 if (vcm->mode == ecmANGULAR)
472 for (g = 0; (g < vcm->nr); g++)
474 tm = vcm->group_mass[g];
479 /* Compute center of mass for this group */
480 for (m = 0; (m < DIM); m++)
482 vcm->group_x[g][m] *= tm_1;
485 /* Subtract the center of mass contribution to the
488 cprod(vcm->group_x[g], vcm->group_v[g], jcm);
489 for (m = 0; (m < DIM); m++)
491 vcm->group_j[g][m] -= tm * jcm[m];
494 /* Subtract the center of mass contribution from the inertia
495 * tensor (this is not as trivial as it seems, but due to
496 * some cancellation we can still do it, even in parallel).
499 update_tensor(vcm->group_x[g], tm, Icm);
500 m_sub(vcm->group_i[g], Icm, vcm->group_i[g]);
502 /* Compute angular velocity, using matrix operation
507 get_minv(vcm->group_i[g], Icm);
508 mvmul(Icm, vcm->group_j[g], vcm->group_w[g]);
510 /* Else it's zero anyway! */
514 for (g = 0; (g < vcm->nr); g++)
517 if (vcm->group_mass[g] != 0 && vcm->group_ndf[g] > 0)
519 for (m = 0; m < vcm->ndim; m++)
521 ekcm += gmx::square(vcm->group_v[g][m]);
523 ekcm *= 0.5 * vcm->group_mass[g];
524 Temp_cm = 2 * ekcm / vcm->group_ndf[g];
526 if ((Temp_cm > Temp_Max) && fp)
528 fprintf(fp, "Large VCM(group %s): %12.5f, %12.5f, %12.5f, Temp-cm: %12.5e\n",
529 vcm->group_name[g], vcm->group_v[g][XX], vcm->group_v[g][YY],
530 vcm->group_v[g][ZZ], Temp_cm);
533 if (vcm->mode == ecmANGULAR)
535 ekrot = 0.5 * iprod(vcm->group_j[g], vcm->group_w[g]);
536 // TODO: Change absolute energy comparison to relative
537 if ((ekrot > 1) && fp && vcm->integratorConservesMomentum)
539 /* if we have an integrator that may not conserve momenta, skip */
540 tm = vcm->group_mass[g];
541 fprintf(fp, "Group %s with mass %12.5e, Ekrot %12.5e Det(I) = %12.5e\n",
542 vcm->group_name[g], tm, ekrot, det(vcm->group_i[g]));
543 fprintf(fp, " COM: %12.5f %12.5f %12.5f\n", vcm->group_x[g][XX],
544 vcm->group_x[g][YY], vcm->group_x[g][ZZ]);
545 fprintf(fp, " P: %12.5f %12.5f %12.5f\n", vcm->group_p[g][XX],
546 vcm->group_p[g][YY], vcm->group_p[g][ZZ]);
547 fprintf(fp, " V: %12.5f %12.5f %12.5f\n", vcm->group_v[g][XX],
548 vcm->group_v[g][YY], vcm->group_v[g][ZZ]);
549 fprintf(fp, " J: %12.5f %12.5f %12.5f\n", vcm->group_j[g][XX],
550 vcm->group_j[g][YY], vcm->group_j[g][ZZ]);
551 fprintf(fp, " w: %12.5f %12.5f %12.5f\n", vcm->group_w[g][XX],
552 vcm->group_w[g][YY], vcm->group_w[g][ZZ]);
553 pr_rvecs(fp, 0, "Inertia tensor", vcm->group_i[g], DIM);
560 void process_and_stopcm_grp(FILE* fplog, t_vcm* vcm, const t_mdatoms& mdatoms, rvec x[], rvec v[])
562 if (vcm->mode != ecmNO)
564 // TODO: Replace fixed temperature of 1 by a system value
565 process_and_check_cm_grp(fplog, vcm, 1);
567 do_stopcm_grp(mdatoms, x, v, *vcm);