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f3bdaa28233d83e4882746b86a8149d290ddd49f
lammps/src/pair.cpp
Axel Kohlmeyer c43fe0a6f6 idiot-proof defining bonds with manybody potentials 
add a test to check if manybody potentials are used with bonds
and (default) exclusion flags that cull pairs from the neighborlist.
now careless use of topology data with resulting in excluded
interactions will generate an error. for the few legitimate use
cases, the test can be turned off.
2013-06-17 21:12:04 +02:00

1630 lines
50 KiB
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/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
/* ----------------------------------------------------------------------
Contributing author: Paul Crozier (SNL)
------------------------------------------------------------------------- */
#include "mpi.h"
#include "float.h"
#include "limits.h"
#include "math.h"
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#include "pair.h"
#include "atom.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "domain.h"
#include "comm.h"
#include "force.h"
#include "kspace.h"
#include "update.h"
#include "accelerator_cuda.h"
#include "suffix.h"
#include "atom_masks.h"
#include "memory.h"
#include "error.h"
using namespace LAMMPS_NS;
#define EWALD_F 1.12837917
enum{RLINEAR,RSQ,BMP};
/* ---------------------------------------------------------------------- */
Pair::Pair(LAMMPS *lmp) : Pointers(lmp)
{
THIRD = 1.0/3.0;
eng_vdwl = eng_coul = 0.0;
comm_forward = comm_reverse = comm_reverse_off = 0;
single_enable = 1;
restartinfo = 1;
respa_enable = 0;
one_coeff = 0;
no_virial_fdotr_compute = 0;
writedata = 0;
ghostneigh = 0;
nextra = 0;
pvector = NULL;
single_extra = 0;
svector = NULL;
ewaldflag = pppmflag = msmflag = dispersionflag = tip4pflag = dipoleflag = 0;
// pair_modify settings
compute_flag = 1;
manybody_flag = 0;
offset_flag = 0;
mix_flag = GEOMETRIC;
tail_flag = 0;
etail = ptail = etail_ij = ptail_ij = 0.0;
ncoultablebits = 12;
ndisptablebits = 12;
tabinner = sqrt(2.0);
tabinner_disp = sqrt(2.0);
allocated = 0;
suffix_flag = Suffix::NONE;
maxeatom = maxvatom = 0;
eatom = NULL;
vatom = NULL;
datamask = ALL_MASK;
datamask_ext = ALL_MASK;
}
/* ---------------------------------------------------------------------- */
Pair::~Pair()
{
memory->destroy(eatom);
memory->destroy(vatom);
}
/* ----------------------------------------------------------------------
modify parameters of the pair style
pair_hybrid has its own version of this routine for its sub-styles
------------------------------------------------------------------------- */
void Pair::modify_params(int narg, char **arg)
{
if (narg == 0) error->all(FLERR,"Illegal pair_modify command");
int iarg = 0;
while (iarg < narg) {
if (strcmp(arg[iarg],"mix") == 0) {
if (iarg+2 > narg) error->all(FLERR,"Illegal pair_modify command");
if (strcmp(arg[iarg+1],"geometric") == 0) mix_flag = GEOMETRIC;
else if (strcmp(arg[iarg+1],"arithmetic") == 0) mix_flag = ARITHMETIC;
else if (strcmp(arg[iarg+1],"sixthpower") == 0) mix_flag = SIXTHPOWER;
else error->all(FLERR,"Illegal pair_modify command");
iarg += 2;
} else if (strcmp(arg[iarg],"shift") == 0) {
if (iarg+2 > narg) error->all(FLERR,"Illegal pair_modify command");
if (strcmp(arg[iarg+1],"yes") == 0) offset_flag = 1;
else if (strcmp(arg[iarg+1],"no") == 0) offset_flag = 0;
else error->all(FLERR,"Illegal pair_modify command");
iarg += 2;
} else if (strcmp(arg[iarg],"table") == 0) {
if (iarg+2 > narg) error->all(FLERR,"Illegal pair_modify command");
ncoultablebits = atoi(arg[iarg+1]);
if (ncoultablebits > sizeof(float)*CHAR_BIT)
error->all(FLERR,"Too many total bits for bitmapped lookup table");
iarg += 2;
} else if (strcmp(arg[iarg],"table/disp") == 0) {
if (iarg+2 > narg) error->all(FLERR,"Illegal pair_modify command");
ndisptablebits = atoi(arg[iarg+1]);
if (ndisptablebits > sizeof(float)*CHAR_BIT)
error->all(FLERR,"Too many total bits for bitmapped lookup table");
iarg += 2;
} else if (strcmp(arg[iarg],"tabinner") == 0) {
if (iarg+2 > narg) error->all(FLERR,"Illegal pair_modify command");
tabinner = atof(arg[iarg+1]);
iarg += 2;
} else if (strcmp(arg[iarg],"tabinner/disp") == 0) {
if (iarg+2 > narg) error->all(FLERR,"Illegal pair_modify command");
tabinner_disp = atof(arg[iarg+1]);
iarg += 2;
} else if (strcmp(arg[iarg],"tail") == 0) {
if (iarg+2 > narg) error->all(FLERR,"Illegal pair_modify command");
if (strcmp(arg[iarg+1],"yes") == 0) tail_flag = 1;
else if (strcmp(arg[iarg+1],"no") == 0) tail_flag = 0;
else error->all(FLERR,"Illegal pair_modify command");
iarg += 2;
} else if (strcmp(arg[iarg],"compute") == 0) {
if (iarg+2 > narg) error->all(FLERR,"Illegal pair_modify command");
if (strcmp(arg[iarg+1],"yes") == 0) compute_flag = 1;
else if (strcmp(arg[iarg+1],"no") == 0) compute_flag = 0;
else error->all(FLERR,"Illegal pair_modify command");
iarg += 2;
} else if (strcmp(arg[iarg],"manybody") == 0) {
if (iarg+2 > narg) error->all(FLERR,"Illegal pair_modify command");
if (strcmp(arg[iarg+1],"yes") == 0) manybody_flag = 1;
else if (strcmp(arg[iarg+1],"no") == 0) manybody_flag = 0;
else error->all(FLERR,"Illegal pair_modify command");
iarg += 2;
} else error->all(FLERR,"Illegal pair_modify command");
}
}
/* ---------------------------------------------------------------------- */
void Pair::init()
{
int i,j;
if (offset_flag && tail_flag)
error->all(FLERR,"Cannot have both pair_modify shift and tail set to yes");
if (tail_flag && domain->dimension == 2)
error->all(FLERR,"Cannot use pair tail corrections with 2d simulations");
if (tail_flag && domain->nonperiodic && comm->me == 0)
error->warning(FLERR,"Using pair tail corrections with nonperiodic system");
// check if possible exclusions could invalidate the neighborlist.
if (manybody_flag && atom->molecular) {
int flag = 0;
if (atom->nbonds > 0 && force->special_lj[1] == 0.0
&& force->special_coul[1] == 0.0) flag = 1;
if (atom->nangles > 0 && force->special_lj[2] == 0.0
&& force->special_coul[2] == 0.0) flag = 1;
if (atom->ndihedrals > 0 && force->special_lj[3] == 0.0
&& force->special_coul[3] == 0.0) flag = 1;
if (flag)
error->all(FLERR,"Using a manybody potential with exclusions");
}
if (!allocated) error->all(FLERR,"All pair coeffs are not set");
// I,I coeffs must be set
// init_one() will check if I,J is set explicitly or inferred by mixing
for (i = 1; i <= atom->ntypes; i++)
if (setflag[i][i] == 0) error->all(FLERR,"All pair coeffs are not set");
// style-specific initialization
init_style();
// call init_one() for each I,J
// set cutsq for each I,J, used to neighbor
// cutforce = max of all I,J cutoffs
cutforce = 0.0;
etail = ptail = 0.0;
double cut;
for (i = 1; i <= atom->ntypes; i++)
for (j = i; j <= atom->ntypes; j++) {
cut = init_one(i,j);
cutsq[i][j] = cutsq[j][i] = cut*cut;
cutforce = MAX(cutforce,cut);
if (tail_flag) {
etail += etail_ij;
ptail += ptail_ij;
if (i != j) {
etail += etail_ij;
ptail += ptail_ij;
}
}
}
}
/* ----------------------------------------------------------------------
reset all type-based params by invoking init_one() for each I,J
called by fix adapt after it changes one or more params
------------------------------------------------------------------------- */
void Pair::reinit()
{
int i,j;
double tmp;
etail = ptail = 0.0;
for (i = 1; i <= atom->ntypes; i++)
for (j = i; j <= atom->ntypes; j++) {
tmp = init_one(i,j);
if (tail_flag) {
etail += etail_ij;
ptail += ptail_ij;
if (i != j) {
etail += etail_ij;
ptail += ptail_ij;
}
}
}
}
/* ----------------------------------------------------------------------
init specific to a pair style
specific pair style can override this function
if needs its own error checks
if needs another kind of neighbor list
request default neighbor list = half list
------------------------------------------------------------------------- */
void Pair::init_style()
{
neighbor->request(this);
}
/* ----------------------------------------------------------------------
neighbor callback to inform pair style of neighbor list to use
specific pair style can override this function
------------------------------------------------------------------------- */
void Pair::init_list(int which, NeighList *ptr)
{
list = ptr;
}
/* ----------------------------------------------------------------------
setup Coulomb force tables used in compute routines
------------------------------------------------------------------------- */
void Pair::init_tables(double cut_coul, double *cut_respa)
{
int masklo,maskhi;
double r,grij,expm2,derfc,egamma,fgamma,rsw;
double qqrd2e = force->qqrd2e;
if (force->kspace == NULL)
error->all(FLERR,"Pair style requres a KSpace style");
double g_ewald = force->kspace->g_ewald;
double cut_coulsq = cut_coul * cut_coul;
tabinnersq = tabinner*tabinner;
init_bitmap(tabinner,cut_coul,ncoultablebits,
masklo,maskhi,ncoulmask,ncoulshiftbits);
int ntable = 1;
for (int i = 0; i < ncoultablebits; i++) ntable *= 2;
// linear lookup tables of length N = 2^ncoultablebits
// stored value = value at lower edge of bin
// d values = delta from lower edge to upper edge of bin
if (ftable) free_tables();
memory->create(rtable,ntable,"pair:rtable");
memory->create(ftable,ntable,"pair:ftable");
memory->create(ctable,ntable,"pair:ctable");
memory->create(etable,ntable,"pair:etable");
memory->create(drtable,ntable,"pair:drtable");
memory->create(dftable,ntable,"pair:dftable");
memory->create(dctable,ntable,"pair:dctable");
memory->create(detable,ntable,"pair:detable");
if (cut_respa == NULL) {
vtable = ptable = dvtable = dptable = NULL;
} else {
memory->create(vtable,ntable,"pair:vtable");
memory->create(ptable,ntable,"pair:ptable");
memory->create(dvtable,ntable,"pair:dvtable");
memory->create(dptable,ntable,"pair:dptable");
}
union_int_float_t rsq_lookup;
union_int_float_t minrsq_lookup;
int itablemin;
minrsq_lookup.i = 0 << ncoulshiftbits;
minrsq_lookup.i |= maskhi;
for (int i = 0; i < ntable; i++) {
rsq_lookup.i = i << ncoulshiftbits;
rsq_lookup.i |= masklo;
if (rsq_lookup.f < tabinnersq) {
rsq_lookup.i = i << ncoulshiftbits;
rsq_lookup.i |= maskhi;
}
r = sqrtf(rsq_lookup.f);
if (msmflag) {
egamma = 1.0 - (r/cut_coul)*force->kspace->gamma(r/cut_coul);
fgamma = 1.0 + (rsq_lookup.f/cut_coulsq)*
force->kspace->dgamma(r/cut_coul);
} else {
grij = g_ewald * r;
expm2 = exp(-grij*grij);
derfc = erfc(grij);
}
if (cut_respa == NULL) {
rtable[i] = rsq_lookup.f;
ctable[i] = qqrd2e/r;
if (msmflag) {
ftable[i] = qqrd2e/r * fgamma;
etable[i] = qqrd2e/r * egamma;
} else {
ftable[i] = qqrd2e/r * (derfc + EWALD_F*grij*expm2);
etable[i] = qqrd2e/r * derfc;
}
} else {
rtable[i] = rsq_lookup.f;
ctable[i] = 0.0;
ptable[i] = qqrd2e/r;
if (msmflag) {
ftable[i] = qqrd2e/r * (fgamma - 1.0);
etable[i] = qqrd2e/r * egamma;
vtable[i] = qqrd2e/r * fgamma;
} else {
ftable[i] = qqrd2e/r * (derfc + EWALD_F*grij*expm2 - 1.0);
etable[i] = qqrd2e/r * derfc;
vtable[i] = qqrd2e/r * (derfc + EWALD_F*grij*expm2);
}
if (rsq_lookup.f > cut_respa[2]*cut_respa[2]) {
if (rsq_lookup.f < cut_respa[3]*cut_respa[3]) {
rsw = (r - cut_respa[2])/(cut_respa[3] - cut_respa[2]);
ftable[i] += qqrd2e/r * rsw*rsw*(3.0 - 2.0*rsw);
ctable[i] = qqrd2e/r * rsw*rsw*(3.0 - 2.0*rsw);
} else {
if (msmflag) ftable[i] = qqrd2e/r * fgamma;
else ftable[i] = qqrd2e/r * (derfc + EWALD_F*grij*expm2);
ctable[i] = qqrd2e/r;
}
}
}
minrsq_lookup.f = MIN(minrsq_lookup.f,rsq_lookup.f);
}
tabinnersq = minrsq_lookup.f;
int ntablem1 = ntable - 1;
for (int i = 0; i < ntablem1; i++) {
drtable[i] = 1.0/(rtable[i+1] - rtable[i]);
dftable[i] = ftable[i+1] - ftable[i];
dctable[i] = ctable[i+1] - ctable[i];
detable[i] = etable[i+1] - etable[i];
}
if (cut_respa) {
for (int i = 0; i < ntablem1; i++) {
dvtable[i] = vtable[i+1] - vtable[i];
dptable[i] = ptable[i+1] - ptable[i];
}
}
// get the delta values for the last table entries
// tables are connected periodically between 0 and ntablem1
drtable[ntablem1] = 1.0/(rtable[0] - rtable[ntablem1]);
dftable[ntablem1] = ftable[0] - ftable[ntablem1];
dctable[ntablem1] = ctable[0] - ctable[ntablem1];
detable[ntablem1] = etable[0] - etable[ntablem1];
if (cut_respa) {
dvtable[ntablem1] = vtable[0] - vtable[ntablem1];
dptable[ntablem1] = ptable[0] - ptable[ntablem1];
}
// get the correct delta values at itablemax
// smallest r is in bin itablemin
// largest r is in bin itablemax, which is itablemin-1,
// or ntablem1 if itablemin=0
// deltas at itablemax only needed if corresponding rsq < cut*cut
// if so, compute deltas between rsq and cut*cut
double f_tmp,c_tmp,e_tmp,p_tmp,v_tmp;
p_tmp = 0.0;
v_tmp = 0.0;
itablemin = minrsq_lookup.i & ncoulmask;
itablemin >>= ncoulshiftbits;
int itablemax = itablemin - 1;
if (itablemin == 0) itablemax = ntablem1;
rsq_lookup.i = itablemax << ncoulshiftbits;
rsq_lookup.i |= maskhi;
if (rsq_lookup.f < cut_coulsq) {
rsq_lookup.f = cut_coulsq;
r = sqrtf(rsq_lookup.f);
if (msmflag) {
egamma = 1.0 - (r/cut_coul)*force->kspace->gamma(r/cut_coul);
fgamma = 1.0 + (rsq_lookup.f/cut_coulsq)*
force->kspace->dgamma(r/cut_coul);
} else {
grij = g_ewald * r;
expm2 = exp(-grij*grij);
derfc = erfc(grij);
}
if (cut_respa == NULL) {
c_tmp = qqrd2e/r;
if (msmflag) {
f_tmp = qqrd2e/r * fgamma;
e_tmp = qqrd2e/r * egamma;
} else {
f_tmp = qqrd2e/r * (derfc + EWALD_F*grij*expm2);
e_tmp = qqrd2e/r * derfc;
}
} else {
c_tmp = 0.0;
p_tmp = qqrd2e/r;
if (msmflag) {
f_tmp = qqrd2e/r * (fgamma - 1.0);
e_tmp = qqrd2e/r * egamma;
v_tmp = qqrd2e/r * fgamma;
} else {
f_tmp = qqrd2e/r * (derfc + EWALD_F*grij*expm2 - 1.0);
e_tmp = qqrd2e/r * derfc;
v_tmp = qqrd2e/r * (derfc + EWALD_F*grij*expm2);
}
if (rsq_lookup.f > cut_respa[2]*cut_respa[2]) {
if (rsq_lookup.f < cut_respa[3]*cut_respa[3]) {
rsw = (r - cut_respa[2])/(cut_respa[3] - cut_respa[2]);
f_tmp += qqrd2e/r * rsw*rsw*(3.0 - 2.0*rsw);
c_tmp = qqrd2e/r * rsw*rsw*(3.0 - 2.0*rsw);
} else {
if (msmflag) f_tmp = qqrd2e/r * fgamma;
else f_tmp = qqrd2e/r * (derfc + EWALD_F*grij*expm2);
c_tmp = qqrd2e/r;
}
}
}
drtable[itablemax] = 1.0/(rsq_lookup.f - rtable[itablemax]);
dftable[itablemax] = f_tmp - ftable[itablemax];
dctable[itablemax] = c_tmp - ctable[itablemax];
detable[itablemax] = e_tmp - etable[itablemax];
if (cut_respa) {
dvtable[itablemax] = v_tmp - vtable[itablemax];
dptable[itablemax] = p_tmp - ptable[itablemax];
}
}
}
/* ----------------------------------------------------------------------
setup force tables for dispersion used in compute routines
------------------------------------------------------------------------- */
void Pair::init_tables_disp(double cut_lj_global)
{
int masklo,maskhi;
double r, rsq, r2inv, force_coul, force_lj;
double g_ewald_6 = force->kspace->g_ewald_6;
double g2 = g_ewald_6*g_ewald_6, g6 = g2*g2*g2, g8 = g6*g2;
tabinnerdispsq = tabinner_disp*tabinner_disp;
init_bitmap(tabinner_disp,cut_lj_global,ndisptablebits,
masklo,maskhi,ndispmask,ndispshiftbits);
int ntable = 1;
for (int i = 0; i < ndisptablebits; i++) ntable *= 2;
// linear lookup tables of length N = 2^ndisptablebits
// stored value = value at lower edge of bin
// d values = delta from lower edge to upper edge of bin
if (fdisptable) free_disp_tables();
memory->create(rdisptable,ntable,"pair:rdisptable");
memory->create(fdisptable,ntable,"pair:fdisptable");
memory->create(edisptable,ntable,"pair:edisptable");
memory->create(drdisptable,ntable,"pair:drdisptable");
memory->create(dfdisptable,ntable,"pair:dfdisptable");
memory->create(dedisptable,ntable,"pair:dedisptable");
union_int_float_t rsq_lookup;
union_int_float_t minrsq_lookup;
int itablemin;
minrsq_lookup.i = 0 << ndispshiftbits;
minrsq_lookup.i |= maskhi;
for (int i = 0; i < ntable; i++) {
rsq_lookup.i = i << ndispshiftbits;
rsq_lookup.i |= masklo;
if (rsq_lookup.f < tabinnerdispsq) {
rsq_lookup.i = i << ndispshiftbits;
rsq_lookup.i |= maskhi;
}
r = sqrtf(rsq_lookup.f);
rsq = rsq_lookup.f;
register double x2 = g2*rsq, a2 = 1.0/x2;
x2 = a2*exp(-x2);
rdisptable[i] = rsq_lookup.f;
fdisptable[i] = g8*(((6.0*a2+6.0)*a2+3.0)*a2+1.0)*x2*rsq;
edisptable[i] = g6*((a2+1.0)*a2+0.5)*x2;
minrsq_lookup.f = MIN(minrsq_lookup.f,rsq_lookup.f);
}
tabinnerdispsq = minrsq_lookup.f;
int ntablem1 = ntable - 1;
for (int i = 0; i < ntablem1; i++) {
drdisptable[i] = 1.0/(rdisptable[i+1] - rdisptable[i]);
dfdisptable[i] = fdisptable[i+1] - fdisptable[i];
dedisptable[i] = edisptable[i+1] - edisptable[i];
}
// get the delta values for the last table entries
// tables are connected periodically between 0 and ntablem1
drdisptable[ntablem1] = 1.0/(rdisptable[0] - rdisptable[ntablem1]);
dfdisptable[ntablem1] = fdisptable[0] - fdisptable[ntablem1];
dedisptable[ntablem1] = edisptable[0] - edisptable[ntablem1];
// get the correct delta values at itablemax
// smallest r is in bin itablemin
// largest r is in bin itablemax, which is itablemin-1,
// or ntablem1 if itablemin=0
// deltas at itablemax only needed if corresponding rsq < cut*cut
// if so, compute deltas between rsq and cut*cut
double f_tmp,c_tmp,e_tmp,p_tmp = 0.0,v_tmp = 0.0;
double cut_lj_globalsq;
itablemin = minrsq_lookup.i & ndispmask;
itablemin >>= ndispshiftbits;
int itablemax = itablemin - 1;
if (itablemin == 0) itablemax = ntablem1;
rsq_lookup.i = itablemax << ndispshiftbits;
rsq_lookup.i |= maskhi;
if (rsq_lookup.f < (cut_lj_globalsq = cut_lj_global * cut_lj_global)) {
rsq_lookup.f = cut_lj_globalsq;
r = sqrtf(rsq_lookup.f);
register double x2 = g2*rsq, a2 = 1.0/x2;
x2 = a2*exp(-x2);
f_tmp = g8*(((6.0*a2+6.0)*a2+3.0)*a2+1.0)*x2*rsq;
e_tmp = g6*((a2+1.0)*a2+0.5)*x2;
drdisptable[itablemax] = 1.0/(rsq_lookup.f - rdisptable[itablemax]);
dfdisptable[itablemax] = f_tmp - fdisptable[itablemax];
dedisptable[itablemax] = e_tmp - edisptable[itablemax];
}
}
/* ----------------------------------------------------------------------
free memory for tables used in Coulombic pair computations
------------------------------------------------------------------------- */
void Pair::free_tables()
{
memory->destroy(rtable);
memory->destroy(drtable);
memory->destroy(ftable);
memory->destroy(dftable);
memory->destroy(ctable);
memory->destroy(dctable);
memory->destroy(etable);
memory->destroy(detable);
memory->destroy(vtable);
memory->destroy(dvtable);
memory->destroy(ptable);
memory->destroy(dptable);
}
/* ----------------------------------------------------------------------
free memory for tables used in pair computations for dispersion
------------------------------------------------------------------------- */
void Pair::free_disp_tables()
{
memory->destroy(rdisptable);
memory->destroy(drdisptable);
memory->destroy(fdisptable);
memory->destroy(dfdisptable);
memory->destroy(edisptable);
memory->destroy(dedisptable);
}
/* ----------------------------------------------------------------------
mixing of pair potential prefactors (epsilon)
------------------------------------------------------------------------- */
double Pair::mix_energy(double eps1, double eps2, double sig1, double sig2)
{
double value;
if (mix_flag == GEOMETRIC)
value = sqrt(eps1*eps2);
else if (mix_flag == ARITHMETIC)
value = sqrt(eps1*eps2);
else if (mix_flag == SIXTHPOWER)
value = 2.0 * sqrt(eps1*eps2) *
pow(sig1,3.0) * pow(sig2,3.0) / (pow(sig1,6.0) + pow(sig2,6.0));
return value;
}
/* ----------------------------------------------------------------------
mixing of pair potential distances (sigma, cutoff)
------------------------------------------------------------------------- */
double Pair::mix_distance(double sig1, double sig2)
{
double value;
if (mix_flag == GEOMETRIC)
value = sqrt(sig1*sig2);
else if (mix_flag == ARITHMETIC)
value = 0.5 * (sig1+sig2);
else if (mix_flag == SIXTHPOWER)
value = pow((0.5 * (pow(sig1,6.0) + pow(sig2,6.0))),1.0/6.0);
return value;
}
/* ---------------------------------------------------------------------- */
void Pair::compute_dummy(int eflag, int vflag)
{
if (eflag || vflag) ev_setup(eflag,vflag);
else evflag = 0;
}
/* ----------------------------------------------------------------------
setup for energy, virial computation
see integrate::ev_set() for values of eflag (0-3) and vflag (0-6)
------------------------------------------------------------------------- */
void Pair::ev_setup(int eflag, int vflag)
{
int i,n;
evflag = 1;
eflag_either = eflag;
eflag_global = eflag % 2;
eflag_atom = eflag / 2;
vflag_either = vflag;
vflag_global = vflag % 4;
vflag_atom = vflag / 4;
// reallocate per-atom arrays if necessary
if (eflag_atom && atom->nmax > maxeatom) {
maxeatom = atom->nmax;
memory->destroy(eatom);
memory->create(eatom,comm->nthreads*maxeatom,"pair:eatom");
}
if (vflag_atom && atom->nmax > maxvatom) {
maxvatom = atom->nmax;
memory->destroy(vatom);
memory->create(vatom,comm->nthreads*maxvatom,6,"pair:vatom");
}
// zero accumulators
// use force->newton instead of newton_pair
// b/c some bonds/dihedrals call pair::ev_tally with pairwise info
if (eflag_global) eng_vdwl = eng_coul = 0.0;
if (vflag_global) for (i = 0; i < 6; i++) virial[i] = 0.0;
if (eflag_atom) {
n = atom->nlocal;
if (force->newton) n += atom->nghost;
for (i = 0; i < n; i++) eatom[i] = 0.0;
}
if (vflag_atom) {
n = atom->nlocal;
if (force->newton) n += atom->nghost;
for (i = 0; i < n; i++) {
vatom[i][0] = 0.0;
vatom[i][1] = 0.0;
vatom[i][2] = 0.0;
vatom[i][3] = 0.0;
vatom[i][4] = 0.0;
vatom[i][5] = 0.0;
}
}
// if vflag_global = 2 and pair::compute() calls virial_fdotr_compute()
// compute global virial via (F dot r) instead of via pairwise summation
// unset other flags as appropriate
if (vflag_global == 2 && no_virial_fdotr_compute == 0) {
vflag_fdotr = 1;
vflag_global = 0;
if (vflag_atom == 0) vflag_either = 0;
if (vflag_either == 0 && eflag_either == 0) evflag = 0;
} else vflag_fdotr = 0;
if (lmp->cuda) lmp->cuda->evsetup_eatom_vatom(eflag_atom,vflag_atom);
}
/* ----------------------------------------------------------------------
set all flags to zero for energy, virial computation
called by some complicated many-body potentials that use individual flags
to insure no holdover of flags from previous timestep
------------------------------------------------------------------------- */
void Pair::ev_unset()
{
evflag = 0;
eflag_either = 0;
eflag_global = 0;
eflag_atom = 0;
vflag_either = 0;
vflag_global = 0;
vflag_atom = 0;
vflag_fdotr = 0;
}
/* ----------------------------------------------------------------------
tally eng_vdwl and virial into global and per-atom accumulators
need i < nlocal test since called by bond_quartic and dihedral_charmm
------------------------------------------------------------------------- */
void Pair::ev_tally(int i, int j, int nlocal, int newton_pair,
double evdwl, double ecoul, double fpair,
double delx, double dely, double delz)
{
double evdwlhalf,ecoulhalf,epairhalf,v[6];
if (eflag_either) {
if (eflag_global) {
if (newton_pair) {
eng_vdwl += evdwl;
eng_coul += ecoul;
} else {
evdwlhalf = 0.5*evdwl;
ecoulhalf = 0.5*ecoul;
if (i < nlocal) {
eng_vdwl += evdwlhalf;
eng_coul += ecoulhalf;
}
if (j < nlocal) {
eng_vdwl += evdwlhalf;
eng_coul += ecoulhalf;
}
}
}
if (eflag_atom) {
epairhalf = 0.5 * (evdwl + ecoul);
if (newton_pair || i < nlocal) eatom[i] += epairhalf;
if (newton_pair || j < nlocal) eatom[j] += epairhalf;
}
}
if (vflag_either) {
v[0] = delx*delx*fpair;
v[1] = dely*dely*fpair;
v[2] = delz*delz*fpair;
v[3] = delx*dely*fpair;
v[4] = delx*delz*fpair;
v[5] = dely*delz*fpair;
if (vflag_global) {
if (newton_pair) {
virial[0] += v[0];
virial[1] += v[1];
virial[2] += v[2];
virial[3] += v[3];
virial[4] += v[4];
virial[5] += v[5];
} else {
if (i < nlocal) {
virial[0] += 0.5*v[0];
virial[1] += 0.5*v[1];
virial[2] += 0.5*v[2];
virial[3] += 0.5*v[3];
virial[4] += 0.5*v[4];
virial[5] += 0.5*v[5];
}
if (j < nlocal) {
virial[0] += 0.5*v[0];
virial[1] += 0.5*v[1];
virial[2] += 0.5*v[2];
virial[3] += 0.5*v[3];
virial[4] += 0.5*v[4];
virial[5] += 0.5*v[5];
}
}
}
if (vflag_atom) {
if (newton_pair || i < nlocal) {
vatom[i][0] += 0.5*v[0];
vatom[i][1] += 0.5*v[1];
vatom[i][2] += 0.5*v[2];
vatom[i][3] += 0.5*v[3];
vatom[i][4] += 0.5*v[4];
vatom[i][5] += 0.5*v[5];
}
if (newton_pair || j < nlocal) {
vatom[j][0] += 0.5*v[0];
vatom[j][1] += 0.5*v[1];
vatom[j][2] += 0.5*v[2];
vatom[j][3] += 0.5*v[3];
vatom[j][4] += 0.5*v[4];
vatom[j][5] += 0.5*v[5];
}
}
}
}
/* ----------------------------------------------------------------------
tally eng_vdwl and virial into global and per-atom accumulators
can use this version with full neighbor lists
------------------------------------------------------------------------- */
void Pair::ev_tally_full(int i, double evdwl, double ecoul, double fpair,
double delx, double dely, double delz)
{
double v[6];
if (eflag_either) {
if (eflag_global) {
eng_vdwl += 0.5*evdwl;
eng_coul += 0.5*ecoul;
}
if (eflag_atom) eatom[i] += 0.5 * (evdwl + ecoul);
}
if (vflag_either) {
v[0] = 0.5*delx*delx*fpair;
v[1] = 0.5*dely*dely*fpair;
v[2] = 0.5*delz*delz*fpair;
v[3] = 0.5*delx*dely*fpair;
v[4] = 0.5*delx*delz*fpair;
v[5] = 0.5*dely*delz*fpair;
if (vflag_global) {
virial[0] += v[0];
virial[1] += v[1];
virial[2] += v[2];
virial[3] += v[3];
virial[4] += v[4];
virial[5] += v[5];
}
if (vflag_atom) {
vatom[i][0] += v[0];
vatom[i][1] += v[1];
vatom[i][2] += v[2];
vatom[i][3] += v[3];
vatom[i][4] += v[4];
vatom[i][5] += v[5];
}
}
}
/* ----------------------------------------------------------------------
tally eng_vdwl and virial into global and per-atom accumulators
for virial, have delx,dely,delz and fx,fy,fz
------------------------------------------------------------------------- */
void Pair::ev_tally_xyz(int i, int j, int nlocal, int newton_pair,
double evdwl, double ecoul,
double fx, double fy, double fz,
double delx, double dely, double delz)
{
double evdwlhalf,ecoulhalf,epairhalf,v[6];
if (eflag_either) {
if (eflag_global) {
if (newton_pair) {
eng_vdwl += evdwl;
eng_coul += ecoul;
} else {
evdwlhalf = 0.5*evdwl;
ecoulhalf = 0.5*ecoul;
if (i < nlocal) {
eng_vdwl += evdwlhalf;
eng_coul += ecoulhalf;
}
if (j < nlocal) {
eng_vdwl += evdwlhalf;
eng_coul += ecoulhalf;
}
}
}
if (eflag_atom) {
epairhalf = 0.5 * (evdwl + ecoul);
if (newton_pair || i < nlocal) eatom[i] += epairhalf;
if (newton_pair || j < nlocal) eatom[j] += epairhalf;
}
}
if (vflag_either) {
v[0] = delx*fx;
v[1] = dely*fy;
v[2] = delz*fz;
v[3] = delx*fy;
v[4] = delx*fz;
v[5] = dely*fz;
if (vflag_global) {
if (newton_pair) {
virial[0] += v[0];
virial[1] += v[1];
virial[2] += v[2];
virial[3] += v[3];
virial[4] += v[4];
virial[5] += v[5];
} else {
if (i < nlocal) {
virial[0] += 0.5*v[0];
virial[1] += 0.5*v[1];
virial[2] += 0.5*v[2];
virial[3] += 0.5*v[3];
virial[4] += 0.5*v[4];
virial[5] += 0.5*v[5];
}
if (j < nlocal) {
virial[0] += 0.5*v[0];
virial[1] += 0.5*v[1];
virial[2] += 0.5*v[2];
virial[3] += 0.5*v[3];
virial[4] += 0.5*v[4];
virial[5] += 0.5*v[5];
}
}
}
if (vflag_atom) {
if (newton_pair || i < nlocal) {
vatom[i][0] += 0.5*v[0];
vatom[i][1] += 0.5*v[1];
vatom[i][2] += 0.5*v[2];
vatom[i][3] += 0.5*v[3];
vatom[i][4] += 0.5*v[4];
vatom[i][5] += 0.5*v[5];
}
if (newton_pair || j < nlocal) {
vatom[j][0] += 0.5*v[0];
vatom[j][1] += 0.5*v[1];
vatom[j][2] += 0.5*v[2];
vatom[j][3] += 0.5*v[3];
vatom[j][4] += 0.5*v[4];
vatom[j][5] += 0.5*v[5];
}
}
}
}
/* ----------------------------------------------------------------------
tally eng_vdwl and virial into global and per-atom accumulators
for virial, have delx,dely,delz and fx,fy,fz
called when using full neighbor lists
------------------------------------------------------------------------- */
void Pair::ev_tally_xyz_full(int i, double evdwl, double ecoul,
double fx, double fy, double fz,
double delx, double dely, double delz)
{
double evdwlhalf,ecoulhalf,epairhalf,v[6];
if (eflag_either) {
if (eflag_global) {
evdwlhalf = 0.5*evdwl;
ecoulhalf = 0.5*ecoul;
eng_vdwl += evdwlhalf;
eng_coul += ecoulhalf;
}
if (eflag_atom) {
epairhalf = 0.5 * (evdwl + ecoul);
eatom[i] += epairhalf;
}
}
if (vflag_either) {
v[0] = 0.5*delx*fx;
v[1] = 0.5*dely*fy;
v[2] = 0.5*delz*fz;
v[3] = 0.5*delx*fy;
v[4] = 0.5*delx*fz;
v[5] = 0.5*dely*fz;
if (vflag_global) {
virial[0] += v[0];
virial[1] += v[1];
virial[2] += v[2];
virial[3] += v[3];
virial[4] += v[4];
virial[5] += v[5];
}
if (vflag_atom) {
vatom[i][0] += v[0];
vatom[i][1] += v[1];
vatom[i][2] += v[2];
vatom[i][3] += v[3];
vatom[i][4] += v[4];
vatom[i][5] += v[5];
}
}
}
/* ----------------------------------------------------------------------
tally eng_vdwl and virial into global and per-atom accumulators
called by SW and hbond potentials, newton_pair is always on
virial = riFi + rjFj + rkFk = (rj-ri) Fj + (rk-ri) Fk = drji*fj + drki*fk
------------------------------------------------------------------------- */
void Pair::ev_tally3(int i, int j, int k, double evdwl, double ecoul,
double *fj, double *fk, double *drji, double *drki)
{
double epairthird,v[6];
if (eflag_either) {
if (eflag_global) {
eng_vdwl += evdwl;
eng_coul += ecoul;
}
if (eflag_atom) {
epairthird = THIRD * (evdwl + ecoul);
eatom[i] += epairthird;
eatom[j] += epairthird;
eatom[k] += epairthird;
}
}
if (vflag_either) {
v[0] = drji[0]*fj[0] + drki[0]*fk[0];
v[1] = drji[1]*fj[1] + drki[1]*fk[1];
v[2] = drji[2]*fj[2] + drki[2]*fk[2];
v[3] = drji[0]*fj[1] + drki[0]*fk[1];
v[4] = drji[0]*fj[2] + drki[0]*fk[2];
v[5] = drji[1]*fj[2] + drki[1]*fk[2];
if (vflag_global) {
virial[0] += v[0];
virial[1] += v[1];
virial[2] += v[2];
virial[3] += v[3];
virial[4] += v[4];
virial[5] += v[5];
}
if (vflag_atom) {
vatom[i][0] += THIRD*v[0]; vatom[i][1] += THIRD*v[1];
vatom[i][2] += THIRD*v[2]; vatom[i][3] += THIRD*v[3];
vatom[i][4] += THIRD*v[4]; vatom[i][5] += THIRD*v[5];
vatom[j][0] += THIRD*v[0]; vatom[j][1] += THIRD*v[1];
vatom[j][2] += THIRD*v[2]; vatom[j][3] += THIRD*v[3];
vatom[j][4] += THIRD*v[4]; vatom[j][5] += THIRD*v[5];
vatom[k][0] += THIRD*v[0]; vatom[k][1] += THIRD*v[1];
vatom[k][2] += THIRD*v[2]; vatom[k][3] += THIRD*v[3];
vatom[k][4] += THIRD*v[4]; vatom[k][5] += THIRD*v[5];
}
}
}
/* ----------------------------------------------------------------------
tally eng_vdwl and virial into global and per-atom accumulators
called by AIREBO potential, newton_pair is always on
------------------------------------------------------------------------- */
void Pair::ev_tally4(int i, int j, int k, int m, double evdwl,
double *fi, double *fj, double *fk,
double *drim, double *drjm, double *drkm)
{
double epairfourth,v[6];
if (eflag_either) {
if (eflag_global) eng_vdwl += evdwl;
if (eflag_atom) {
epairfourth = 0.25 * evdwl;
eatom[i] += epairfourth;
eatom[j] += epairfourth;
eatom[k] += epairfourth;
eatom[m] += epairfourth;
}
}
if (vflag_atom) {
v[0] = 0.25 * (drim[0]*fi[0] + drjm[0]*fj[0] + drkm[0]*fk[0]);
v[1] = 0.25 * (drim[1]*fi[1] + drjm[1]*fj[1] + drkm[1]*fk[1]);
v[2] = 0.25 * (drim[2]*fi[2] + drjm[2]*fj[2] + drkm[2]*fk[2]);
v[3] = 0.25 * (drim[0]*fi[1] + drjm[0]*fj[1] + drkm[0]*fk[1]);
v[4] = 0.25 * (drim[0]*fi[2] + drjm[0]*fj[2] + drkm[0]*fk[2]);
v[5] = 0.25 * (drim[1]*fi[2] + drjm[1]*fj[2] + drkm[1]*fk[2]);
vatom[i][0] += v[0]; vatom[i][1] += v[1]; vatom[i][2] += v[2];
vatom[i][3] += v[3]; vatom[i][4] += v[4]; vatom[i][5] += v[5];
vatom[j][0] += v[0]; vatom[j][1] += v[1]; vatom[j][2] += v[2];
vatom[j][3] += v[3]; vatom[j][4] += v[4]; vatom[j][5] += v[5];
vatom[k][0] += v[0]; vatom[k][1] += v[1]; vatom[k][2] += v[2];
vatom[k][3] += v[3]; vatom[k][4] += v[4]; vatom[k][5] += v[5];
vatom[m][0] += v[0]; vatom[m][1] += v[1]; vatom[m][2] += v[2];
vatom[m][3] += v[3]; vatom[m][4] += v[4]; vatom[m][5] += v[5];
}
}
/* ----------------------------------------------------------------------
tally ecoul and virial into each of atoms in list
called by TIP4P potential, newton_pair is always on
weight assignments by alpha, so contribution is all to O atom as alpha -> 0.0
key = 0 if neither atom = water O
key = 1 if first atom = water O
key = 2 if second atom = water O
key = 3 if both atoms = water O
------------------------------------------------------------------------- */
void Pair::ev_tally_tip4p(int key, int *list, double *v,
double ecoul, double alpha)
{
int i,j;
if (eflag_either) {
if (eflag_global) eng_coul += ecoul;
if (eflag_atom) {
if (key == 0) {
eatom[list[0]] += 0.5*ecoul;
eatom[list[1]] += 0.5*ecoul;
} else if (key == 1) {
eatom[list[0]] += 0.5*ecoul*(1-alpha);
eatom[list[1]] += 0.25*ecoul*alpha;
eatom[list[2]] += 0.25*ecoul*alpha;
eatom[list[3]] += 0.5*ecoul;
} else if (key == 2) {
eatom[list[0]] += 0.5*ecoul;
eatom[list[1]] += 0.5*ecoul*(1-alpha);
eatom[list[2]] += 0.25*ecoul*alpha;
eatom[list[3]] += 0.25*ecoul*alpha;
} else {
eatom[list[0]] += 0.5*ecoul*(1-alpha);
eatom[list[1]] += 0.25*ecoul*alpha;
eatom[list[2]] += 0.25*ecoul*alpha;
eatom[list[3]] += 0.5*ecoul*(1-alpha);
eatom[list[4]] += 0.25*ecoul*alpha;
eatom[list[5]] += 0.25*ecoul*alpha;
}
}
}
if (vflag_either) {
if (vflag_global) {
virial[0] += v[0];
virial[1] += v[1];
virial[2] += v[2];
virial[3] += v[3];
virial[4] += v[4];
virial[5] += v[5];
}
if (vflag_atom) {
if (key == 0) {
for (i = 0; i <= 5; i++) {
vatom[list[0]][i] += 0.5*v[i];
vatom[list[1]][i] += 0.5*v[i];
}
} else if (key == 1) {
for (i = 0; i <= 5; i++) {
vatom[list[0]][i] += 0.5*v[i]*(1-alpha);
vatom[list[1]][i] += 0.25*v[i]*alpha;
vatom[list[2]][i] += 0.25*v[i]*alpha;
vatom[list[3]][i] += 0.5*v[i];
}
} else if (key == 2) {
for (i = 0; i <= 5; i++) {
vatom[list[0]][i] += 0.5*v[i];
vatom[list[1]][i] += 0.5*v[i]*(1-alpha);
vatom[list[2]][i] += 0.25*v[i]*alpha;
vatom[list[3]][i] += 0.25*v[i]*alpha;
}
} else {
for (i = 0; i <= 5; i++) {
vatom[list[0]][i] += 0.5*v[i]*(1-alpha);
vatom[list[1]][i] += 0.25*v[i]*alpha;
vatom[list[2]][i] += 0.25*v[i]*alpha;
vatom[list[3]][i] += 0.5*v[i]*(1-alpha);
vatom[list[4]][i] += 0.25*v[i]*alpha;
vatom[list[5]][i] += 0.25*v[i]*alpha;
}
}
}
}
}
/* ----------------------------------------------------------------------
tally virial into per-atom accumulators
called by REAX/C potential, newton_pair is always on
fi is magnitude of force on atom i
------------------------------------------------------------------------- */
void Pair::v_tally(int i, double *fi, double *deli)
{
double v[6];
v[0] = 0.5*deli[0]*fi[0];
v[1] = 0.5*deli[1]*fi[1];
v[2] = 0.5*deli[2]*fi[2];
v[3] = 0.5*deli[0]*fi[1];
v[4] = 0.5*deli[0]*fi[2];
v[5] = 0.5*deli[1]*fi[2];
vatom[i][0] += v[0]; vatom[i][1] += v[1]; vatom[i][2] += v[2];
vatom[i][3] += v[3]; vatom[i][4] += v[4]; vatom[i][5] += v[5];
}
/* ----------------------------------------------------------------------
tally virial into per-atom accumulators
called by AIREBO potential, newton_pair is always on
fpair is magnitude of force on atom I
------------------------------------------------------------------------- */
void Pair::v_tally2(int i, int j, double fpair, double *drij)
{
double v[6];
v[0] = 0.5 * drij[0]*drij[0]*fpair;
v[1] = 0.5 * drij[1]*drij[1]*fpair;
v[2] = 0.5 * drij[2]*drij[2]*fpair;
v[3] = 0.5 * drij[0]*drij[1]*fpair;
v[4] = 0.5 * drij[0]*drij[2]*fpair;
v[5] = 0.5 * drij[1]*drij[2]*fpair;
vatom[i][0] += v[0]; vatom[i][1] += v[1]; vatom[i][2] += v[2];
vatom[i][3] += v[3]; vatom[i][4] += v[4]; vatom[i][5] += v[5];
vatom[j][0] += v[0]; vatom[j][1] += v[1]; vatom[j][2] += v[2];
vatom[j][3] += v[3]; vatom[j][4] += v[4]; vatom[j][5] += v[5];
}
/* ----------------------------------------------------------------------
tally virial into per-atom accumulators
called by AIREBO and Tersoff potential, newton_pair is always on
------------------------------------------------------------------------- */
void Pair::v_tally3(int i, int j, int k,
double *fi, double *fj, double *drik, double *drjk)
{
double v[6];
v[0] = THIRD * (drik[0]*fi[0] + drjk[0]*fj[0]);
v[1] = THIRD * (drik[1]*fi[1] + drjk[1]*fj[1]);
v[2] = THIRD * (drik[2]*fi[2] + drjk[2]*fj[2]);
v[3] = THIRD * (drik[0]*fi[1] + drjk[0]*fj[1]);
v[4] = THIRD * (drik[0]*fi[2] + drjk[0]*fj[2]);
v[5] = THIRD * (drik[1]*fi[2] + drjk[1]*fj[2]);
vatom[i][0] += v[0]; vatom[i][1] += v[1]; vatom[i][2] += v[2];
vatom[i][3] += v[3]; vatom[i][4] += v[4]; vatom[i][5] += v[5];
vatom[j][0] += v[0]; vatom[j][1] += v[1]; vatom[j][2] += v[2];
vatom[j][3] += v[3]; vatom[j][4] += v[4]; vatom[j][5] += v[5];
vatom[k][0] += v[0]; vatom[k][1] += v[1]; vatom[k][2] += v[2];
vatom[k][3] += v[3]; vatom[k][4] += v[4]; vatom[k][5] += v[5];
}
/* ----------------------------------------------------------------------
tally virial into per-atom accumulators
called by AIREBO potential, newton_pair is always on
------------------------------------------------------------------------- */
void Pair::v_tally4(int i, int j, int k, int m,
double *fi, double *fj, double *fk,
double *drim, double *drjm, double *drkm)
{
double v[6];
v[0] = 0.25 * (drim[0]*fi[0] + drjm[0]*fj[0] + drkm[0]*fk[0]);
v[1] = 0.25 * (drim[1]*fi[1] + drjm[1]*fj[1] + drkm[1]*fk[1]);
v[2] = 0.25 * (drim[2]*fi[2] + drjm[2]*fj[2] + drkm[2]*fk[2]);
v[3] = 0.25 * (drim[0]*fi[1] + drjm[0]*fj[1] + drkm[0]*fk[1]);
v[4] = 0.25 * (drim[0]*fi[2] + drjm[0]*fj[2] + drkm[0]*fk[2]);
v[5] = 0.25 * (drim[1]*fi[2] + drjm[1]*fj[2] + drkm[1]*fk[2]);
vatom[i][0] += v[0]; vatom[i][1] += v[1]; vatom[i][2] += v[2];
vatom[i][3] += v[3]; vatom[i][4] += v[4]; vatom[i][5] += v[5];
vatom[j][0] += v[0]; vatom[j][1] += v[1]; vatom[j][2] += v[2];
vatom[j][3] += v[3]; vatom[j][4] += v[4]; vatom[j][5] += v[5];
vatom[k][0] += v[0]; vatom[k][1] += v[1]; vatom[k][2] += v[2];
vatom[k][3] += v[3]; vatom[k][4] += v[4]; vatom[k][5] += v[5];
vatom[m][0] += v[0]; vatom[m][1] += v[1]; vatom[m][2] += v[2];
vatom[m][3] += v[3]; vatom[m][4] += v[4]; vatom[m][5] += v[5];
}
/* ----------------------------------------------------------------------
tally virial into global and per-atom accumulators
called by pair lubricate potential with 6 tensor components
------------------------------------------------------------------------- */
void Pair::v_tally_tensor(int i, int j, int nlocal, int newton_pair,
double vxx, double vyy, double vzz,
double vxy, double vxz, double vyz)
{
double v[6];
v[0] = vxx;
v[1] = vyy;
v[2] = vzz;
v[3] = vxy;
v[4] = vxz;
v[5] = vyz;
if (vflag_global) {
if (newton_pair) {
virial[0] += v[0];
virial[1] += v[1];
virial[2] += v[2];
virial[3] += v[3];
virial[4] += v[4];
virial[5] += v[5];
} else {
if (i < nlocal) {
virial[0] += 0.5*v[0];
virial[1] += 0.5*v[1];
virial[2] += 0.5*v[2];
virial[3] += 0.5*v[3];
virial[4] += 0.5*v[4];
virial[5] += 0.5*v[5];
}
if (j < nlocal) {
virial[0] += 0.5*v[0];
virial[1] += 0.5*v[1];
virial[2] += 0.5*v[2];
virial[3] += 0.5*v[3];
virial[4] += 0.5*v[4];
virial[5] += 0.5*v[5];
}
}
}
if (vflag_atom) {
if (newton_pair || i < nlocal) {
vatom[i][0] += 0.5*v[0];
vatom[i][1] += 0.5*v[1];
vatom[i][2] += 0.5*v[2];
vatom[i][3] += 0.5*v[3];
vatom[i][4] += 0.5*v[4];
vatom[i][5] += 0.5*v[5];
}
if (newton_pair || j < nlocal) {
vatom[j][0] += 0.5*v[0];
vatom[j][1] += 0.5*v[1];
vatom[j][2] += 0.5*v[2];
vatom[j][3] += 0.5*v[3];
vatom[j][4] += 0.5*v[4];
vatom[j][5] += 0.5*v[5];
}
}
}
/* ----------------------------------------------------------------------
compute global pair virial via summing F dot r over own & ghost atoms
at this point, only pairwise forces have been accumulated in atom->f
------------------------------------------------------------------------- */
void Pair::virial_fdotr_compute()
{
double **x = atom->x;
double **f = atom->f;
// sum over force on all particles including ghosts
if (neighbor->includegroup == 0) {
int nall = atom->nlocal + atom->nghost;
for (int i = 0; i < nall; i++) {
virial[0] += f[i][0]*x[i][0];
virial[1] += f[i][1]*x[i][1];
virial[2] += f[i][2]*x[i][2];
virial[3] += f[i][1]*x[i][0];
virial[4] += f[i][2]*x[i][0];
virial[5] += f[i][2]*x[i][1];
}
// neighbor includegroup flag is set
// sum over force on initial nfirst particles and ghosts
} else {
int nall = atom->nfirst;
for (int i = 0; i < nall; i++) {
virial[0] += f[i][0]*x[i][0];
virial[1] += f[i][1]*x[i][1];
virial[2] += f[i][2]*x[i][2];
virial[3] += f[i][1]*x[i][0];
virial[4] += f[i][2]*x[i][0];
virial[5] += f[i][2]*x[i][1];
}
nall = atom->nlocal + atom->nghost;
for (int i = atom->nlocal; i < nall; i++) {
virial[0] += f[i][0]*x[i][0];
virial[1] += f[i][1]*x[i][1];
virial[2] += f[i][2]*x[i][2];
virial[3] += f[i][1]*x[i][0];
virial[4] += f[i][2]*x[i][0];
virial[5] += f[i][2]*x[i][1];
}
}
}
/* ----------------------------------------------------------------------
write a table of pair potential energy/force vs distance to a file
------------------------------------------------------------------------- */
void Pair::write_file(int narg, char **arg)
{
if (narg < 8) error->all(FLERR,"Illegal pair_write command");
if (single_enable == 0)
error->all(FLERR,"Pair style does not support pair_write");
// parse arguments
int itype = atoi(arg[0]);
int jtype = atoi(arg[1]);
if (itype < 1 || itype > atom->ntypes || jtype < 1 || jtype > atom->ntypes)
error->all(FLERR,"Invalid atom types in pair_write command");
int n = atoi(arg[2]);
int style;
if (strcmp(arg[3],"r") == 0) style = RLINEAR;
else if (strcmp(arg[3],"rsq") == 0) style = RSQ;
else if (strcmp(arg[3],"bitmap") == 0) style = BMP;
else error->all(FLERR,"Invalid style in pair_write command");
double inner = atof(arg[4]);
double outer = atof(arg[5]);
if (inner <= 0.0 || inner >= outer)
error->all(FLERR,"Invalid cutoffs in pair_write command");
// open file in append mode
// print header in format used by pair_style table
int me;
MPI_Comm_rank(world,&me);
FILE *fp;
if (me == 0) {
fp = fopen(arg[6],"a");
if (fp == NULL) error->one(FLERR,"Cannot open pair_write file");
fprintf(fp,"# Pair potential %s for atom types %d %d: i,r,energy,force\n",
force->pair_style,itype,jtype);
if (style == RLINEAR)
fprintf(fp,"\n%s\nN %d R %g %g\n\n",arg[7],n,inner,outer);
if (style == RSQ)
fprintf(fp,"\n%s\nN %d RSQ %g %g\n\n",arg[7],n,inner,outer);
}
// initialize potentials before evaluating pair potential
// insures all pair coeffs are set and force constants
force->init();
// if pair style = any of EAM, swap in dummy fp vector
double eamfp[2];
eamfp[0] = eamfp[1] = 0.0;
double *eamfp_hold;
Pair *epair = force->pair_match("eam",0);
if (epair) epair->swap_eam(eamfp,&eamfp_hold);
// if atom style defines charge, swap in dummy q vec
double q[2];
q[0] = q[1] = 1.0;
if (narg == 10) {
q[0] = atof(arg[8]);
q[1] = atof(arg[9]);
}
double *q_hold;
if (atom->q) {
q_hold = atom->q;
atom->q = q;
}
// evaluate energy and force at each of N distances
int masklo,maskhi,nmask,nshiftbits;
if (style == BMP) {
init_bitmap(inner,outer,n,masklo,maskhi,nmask,nshiftbits);
int ntable = 1 << n;
if (me == 0)
fprintf(fp,"\n%s\nN %d BITMAP %g %g\n\n",arg[7],ntable,inner,outer);
n = ntable;
}
double r,e,f,rsq;
union_int_float_t rsq_lookup;
for (int i = 0; i < n; i++) {
if (style == RLINEAR) {
r = inner + (outer-inner) * i/(n-1);
rsq = r*r;
} else if (style == RSQ) {
rsq = inner*inner + (outer*outer - inner*inner) * i/(n-1);
r = sqrt(rsq);
} else if (style == BMP) {
rsq_lookup.i = i << nshiftbits;
rsq_lookup.i |= masklo;
if (rsq_lookup.f < inner*inner) {
rsq_lookup.i = i << nshiftbits;
rsq_lookup.i |= maskhi;
}
rsq = rsq_lookup.f;
r = sqrt(rsq);
}
if (rsq < cutsq[itype][jtype]) {
e = single(0,1,itype,jtype,rsq,1.0,1.0,f);
f *= r;
} else e = f = 0.0;
if (me == 0) fprintf(fp,"%d %g %g %g\n",i+1,r,e,f);
}
// restore original vecs that were swapped in for
double *tmp;
if (epair) epair->swap_eam(eamfp_hold,&tmp);
if (atom->q) atom->q = q_hold;
if (me == 0) fclose(fp);
}
/* ----------------------------------------------------------------------
define bitmap parameters based on inner and outer cutoffs
------------------------------------------------------------------------- */
void Pair::init_bitmap(double inner, double outer, int ntablebits,
int &masklo, int &maskhi, int &nmask, int &nshiftbits)
{
if (sizeof(int) != sizeof(float))
error->all(FLERR,"Bitmapped lookup tables require int/float be same size");
if (ntablebits > sizeof(float)*CHAR_BIT)
error->all(FLERR,"Too many total bits for bitmapped lookup table");
if (inner >= outer)
error->warning(FLERR,"Table inner cutoff >= outer cutoff");
int nlowermin = 1;
while (!((pow(double(2),(double)nlowermin) <= inner*inner) &&
(pow(double(2),(double)nlowermin+1.0) > inner*inner))) {
if (pow(double(2),(double)nlowermin) <= inner*inner) nlowermin++;
else nlowermin--;
}
int nexpbits = 0;
double required_range = outer*outer / pow(double(2),(double)nlowermin);
double available_range = 2.0;
while (available_range < required_range) {
nexpbits++;
available_range = pow(double(2),pow(double(2),(double)nexpbits));
}
int nmantbits = ntablebits - nexpbits;
if (nexpbits > sizeof(float)*CHAR_BIT - FLT_MANT_DIG)
error->all(FLERR,"Too many exponent bits for lookup table");
if (nmantbits+1 > FLT_MANT_DIG)
error->all(FLERR,"Too many mantissa bits for lookup table");
if (nmantbits < 3) error->all(FLERR,"Too few bits for lookup table");
nshiftbits = FLT_MANT_DIG - (nmantbits+1);
nmask = 1;
for (int j = 0; j < ntablebits+nshiftbits; j++) nmask *= 2;
nmask -= 1;
union_int_float_t rsq_lookup;
rsq_lookup.f = outer*outer;
maskhi = rsq_lookup.i & ~(nmask);
rsq_lookup.f = inner*inner;
masklo = rsq_lookup.i & ~(nmask);
}
/* ---------------------------------------------------------------------- */
double Pair::memory_usage()
{
double bytes = comm->nthreads*maxeatom * sizeof(double);
bytes += comm->nthreads*maxvatom*6 * sizeof(double);
return bytes;
}
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