Page Menu
Home
c4science
Search
Configure Global Search
Log In
Files
F80782627
pair_lj_long_dipole_long.cpp
No One
Temporary
Actions
Download File
Edit File
Delete File
View Transforms
Subscribe
Mute Notifications
Award Token
Subscribers
None
File Metadata
Details
File Info
Storage
Attached
Created
Mon, Sep 2, 14:01
Size
22 KB
Mime Type
text/x-c
Expires
Wed, Sep 4, 14:01 (1 d, 21 h)
Engine
blob
Format
Raw Data
Handle
20298787
Attached To
rLAMMPS lammps
pair_lj_long_dipole_long.cpp
View Options
/* ----------------------------------------------------------------------
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: Pieter J. in 't Veld and Stan Moore (Sandia)
------------------------------------------------------------------------- */
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "math_const.h"
#include "math_vector.h"
#include "pair_lj_long_dipole_long.h"
#include "atom.h"
#include "comm.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "neigh_request.h"
#include "force.h"
#include "kspace.h"
#include "update.h"
#include "integrate.h"
#include "respa.h"
#include "memory.h"
#include "error.h"
using namespace LAMMPS_NS;
using namespace MathConst;
#define EWALD_F 1.12837917
#define EWALD_P 0.3275911
#define A1 0.254829592
#define A2 -0.284496736
#define A3 1.421413741
#define A4 -1.453152027
#define A5 1.061405429
// ----------------------------------------------------------------------
PairLJLongDipoleLong::PairLJLongDipoleLong(LAMMPS *lmp) : Pair(lmp)
{
dispersionflag = ewaldflag = dipoleflag = 1;
respa_enable = 0;
single_enable = 0;
}
// ----------------------------------------------------------------------
// global settings
// ----------------------------------------------------------------------
void PairLJLongDipoleLong::options(char **arg, int order)
{
const char *option[] = {"long", "cut", "off", NULL};
int i;
if (!*arg) error->all(FLERR,"Illegal pair_style lj/long/dipole/long command");
for (i=0; option[i]&&strcmp(arg[0], option[i]); ++i);
switch (i) {
default: error->all(FLERR,"Illegal pair_style lj/long/dipole/long command");
case 0: ewald_order |= 1<<order; break; // set kspace r^-order
case 2: ewald_off |= 1<<order; // turn r^-order off
case 1: break;
}
}
void PairLJLongDipoleLong::settings(int narg, char **arg)
{
if (narg != 3 && narg != 4) error->all(FLERR,"Illegal pair_style command");
ewald_off = 0;
ewald_order = 0;
options(arg, 6);
options(++arg, 3);
options(arg, 1);
if (!comm->me && ewald_order&(1<<6))
error->warning(FLERR,"Geometric mixing assumed for 1/r^6 coefficients");
if (!comm->me && ewald_order==((1<<3)|(1<<6)))
error->warning(FLERR,
"Using largest cut-off for lj/long/dipole/long long long");
if (!*(++arg))
error->all(FLERR,"Cut-offs missing in pair_style lj/long/dipole/long");
if (!((ewald_order^ewald_off)&(1<<3)))
error->all(FLERR,
"Coulombic cut not supported in pair_style lj/long/dipole/long");
cut_lj_global = force->numeric(FLERR,*(arg++));
if (narg == 4 && (ewald_order==74))
error->all(FLERR,"Only one cut-off allowed when requesting all long");
if (narg == 4) cut_coul = force->numeric(FLERR,*(arg++));
else cut_coul = cut_lj_global;
if (allocated) { // reset explicit cuts
int i,j;
for (i = 1; i <= atom->ntypes; i++)
for (j = i+1; j <= atom->ntypes; j++)
if (setflag[i][j]) cut_lj[i][j] = cut_lj_global;
}
}
// ----------------------------------------------------------------------
// free all arrays
// ----------------------------------------------------------------------
PairLJLongDipoleLong::~PairLJLongDipoleLong()
{
if (allocated) {
memory->destroy(setflag);
memory->destroy(cutsq);
memory->destroy(cut_lj_read);
memory->destroy(cut_lj);
memory->destroy(cut_ljsq);
memory->destroy(epsilon_read);
memory->destroy(epsilon);
memory->destroy(sigma_read);
memory->destroy(sigma);
memory->destroy(lj1);
memory->destroy(lj2);
memory->destroy(lj3);
memory->destroy(lj4);
memory->destroy(offset);
}
//if (ftable) free_tables();
}
/* ----------------------------------------------------------------------
allocate all arrays
------------------------------------------------------------------------- */
void PairLJLongDipoleLong::allocate()
{
allocated = 1;
int n = atom->ntypes;
memory->create(setflag,n+1,n+1,"pair:setflag");
for (int i = 1; i <= n; i++)
for (int j = i; j <= n; j++)
setflag[i][j] = 0;
memory->create(cutsq,n+1,n+1,"pair:cutsq");
memory->create(cut_lj_read,n+1,n+1,"pair:cut_lj_read");
memory->create(cut_lj,n+1,n+1,"pair:cut_lj");
memory->create(cut_ljsq,n+1,n+1,"pair:cut_ljsq");
memory->create(epsilon_read,n+1,n+1,"pair:epsilon_read");
memory->create(epsilon,n+1,n+1,"pair:epsilon");
memory->create(sigma_read,n+1,n+1,"pair:sigma_read");
memory->create(sigma,n+1,n+1,"pair:sigma");
memory->create(lj1,n+1,n+1,"pair:lj1");
memory->create(lj2,n+1,n+1,"pair:lj2");
memory->create(lj3,n+1,n+1,"pair:lj3");
memory->create(lj4,n+1,n+1,"pair:lj4");
memory->create(offset,n+1,n+1,"pair:offset");
}
/* ----------------------------------------------------------------------
extract protected data from object
------------------------------------------------------------------------- */
void *PairLJLongDipoleLong::extract(const char *id, int &dim)
{
const char *ids[] = {
"B", "sigma", "epsilon", "ewald_order", "ewald_cut", "ewald_mix",
"cut_coul", "cut_vdwl", NULL};
void *ptrs[] = {
lj4, sigma, epsilon, &ewald_order, &cut_coul, &mix_flag, &cut_coul,
&cut_lj_global, NULL};
int i;
for (i=0; ids[i]&&strcmp(ids[i], id); ++i);
if (i <= 2) dim = 2;
else dim = 0;
return ptrs[i];
}
/* ----------------------------------------------------------------------
set coeffs for one or more type pairs
------------------------------------------------------------------------- */
void PairLJLongDipoleLong::coeff(int narg, char **arg)
{
if (narg < 4 || narg > 5)
error->all(FLERR,"Incorrect args for pair coefficients");
if (!allocated) allocate();
int ilo,ihi,jlo,jhi;
force->bounds(arg[0],atom->ntypes,ilo,ihi);
force->bounds(arg[1],atom->ntypes,jlo,jhi);
double epsilon_one = force->numeric(FLERR,arg[2]);
double sigma_one = force->numeric(FLERR,arg[3]);
double cut_lj_one = cut_lj_global;
if (narg == 5) cut_lj_one = force->numeric(FLERR,arg[4]);
int count = 0;
for (int i = ilo; i <= ihi; i++) {
for (int j = MAX(jlo,i); j <= jhi; j++) {
epsilon_read[i][j] = epsilon_one;
sigma_read[i][j] = sigma_one;
cut_lj_read[i][j] = cut_lj_one;
setflag[i][j] = 1;
count++;
}
}
if (count == 0) error->all(FLERR,"Incorrect args for pair coefficients");
}
/* ----------------------------------------------------------------------
init specific to this pair style
------------------------------------------------------------------------- */
void PairLJLongDipoleLong::init_style()
{
const char *style3[] = {"ewald/disp", NULL};
const char *style6[] = {"ewald/disp", NULL};
int i;
if (strcmp(update->unit_style,"electron") == 0)
error->all(FLERR,"Cannot (yet) use 'electron' units with dipoles");
// require an atom style with charge defined
if (!atom->q_flag && (ewald_order&(1<<1)))
error->all(FLERR,
"Invoking coulombic in pair style lj/long/dipole/long requires atom attribute q");
if (!atom->mu && (ewald_order&(1<<3)))
error->all(FLERR,"Pair lj/long/dipole/long requires atom attributes mu, torque");
if (!atom->torque && (ewald_order&(1<<3)))
error->all(FLERR,"Pair lj/long/dipole/long requires atom attributes mu, torque");
neighbor->request(this,instance_me);
cut_coulsq = cut_coul * cut_coul;
// ensure use of KSpace long-range solver, set g_ewald
if (ewald_order&(1<<3)) { // r^-1 kspace
if (force->kspace == NULL)
error->all(FLERR,"Pair style requires a KSpace style");
for (i=0; style3[i]&&strcmp(force->kspace_style, style3[i]); ++i);
if (!style3[i])
error->all(FLERR,"Pair style requires use of kspace_style ewald/disp");
}
if (ewald_order&(1<<6)) { // r^-6 kspace
if (force->kspace == NULL)
error->all(FLERR,"Pair style requires a KSpace style");
for (i=0; style6[i]&&strcmp(force->kspace_style, style6[i]); ++i);
if (!style6[i])
error->all(FLERR,"Pair style requires use of kspace_style ewald/disp");
}
if (force->kspace) g_ewald = force->kspace->g_ewald;
}
/* ----------------------------------------------------------------------
neighbor callback to inform pair style of neighbor list to use
regular or rRESPA
------------------------------------------------------------------------- */
void PairLJLongDipoleLong::init_list(int id, NeighList *ptr)
{
if (id == 0) list = ptr;
else if (id == 1) listinner = ptr;
else if (id == 2) listmiddle = ptr;
else if (id == 3) listouter = ptr;
if (id)
error->all(FLERR,"Pair style lj/long/dipole/long does not currently support respa");
}
/* ----------------------------------------------------------------------
init for one type pair i,j and corresponding j,i
------------------------------------------------------------------------- */
double PairLJLongDipoleLong::init_one(int i, int j)
{
if ((ewald_order&(1<<6))||(setflag[i][j] == 0)) {
epsilon[i][j] = mix_energy(epsilon_read[i][i],epsilon_read[j][j],
sigma_read[i][i],sigma_read[j][j]);
sigma[i][j] = mix_distance(sigma_read[i][i],sigma_read[j][j]);
if (ewald_order&(1<<6))
cut_lj[i][j] = cut_lj_global;
else
cut_lj[i][j] = mix_distance(cut_lj_read[i][i],cut_lj_read[j][j]);
}
else {
sigma[i][j] = sigma_read[i][j];
epsilon[i][j] = epsilon_read[i][j];
cut_lj[i][j] = cut_lj_read[i][j];
}
double cut = MAX(cut_lj[i][j], cut_coul);
cutsq[i][j] = cut*cut;
cut_ljsq[i][j] = cut_lj[i][j] * cut_lj[i][j];
lj1[i][j] = 48.0 * epsilon[i][j] * pow(sigma[i][j],12.0);
lj2[i][j] = 24.0 * epsilon[i][j] * pow(sigma[i][j],6.0);
lj3[i][j] = 4.0 * epsilon[i][j] * pow(sigma[i][j],12.0);
lj4[i][j] = 4.0 * epsilon[i][j] * pow(sigma[i][j],6.0);
// check interior rRESPA cutoff
//if (cut_respa && MIN(cut_lj[i][j],cut_coul) < cut_respa[3])
//error->all(FLERR,"Pair cutoff < Respa interior cutoff");
if (offset_flag) {
double ratio = sigma[i][j] / cut_lj[i][j];
offset[i][j] = 4.0 * epsilon[i][j] * (pow(ratio,12.0) - pow(ratio,6.0));
} else offset[i][j] = 0.0;
cutsq[j][i] = cutsq[i][j];
cut_ljsq[j][i] = cut_ljsq[i][j];
lj1[j][i] = lj1[i][j];
lj2[j][i] = lj2[i][j];
lj3[j][i] = lj3[i][j];
lj4[j][i] = lj4[i][j];
offset[j][i] = offset[i][j];
return cut;
}
/* ----------------------------------------------------------------------
proc 0 writes to restart file
------------------------------------------------------------------------- */
void PairLJLongDipoleLong::write_restart(FILE *fp)
{
write_restart_settings(fp);
int i,j;
for (i = 1; i <= atom->ntypes; i++)
for (j = i; j <= atom->ntypes; j++) {
fwrite(&setflag[i][j],sizeof(int),1,fp);
if (setflag[i][j]) {
fwrite(&epsilon_read[i][j],sizeof(double),1,fp);
fwrite(&sigma_read[i][j],sizeof(double),1,fp);
fwrite(&cut_lj_read[i][j],sizeof(double),1,fp);
}
}
}
/* ----------------------------------------------------------------------
proc 0 reads from restart file, bcasts
------------------------------------------------------------------------- */
void PairLJLongDipoleLong::read_restart(FILE *fp)
{
read_restart_settings(fp);
allocate();
int i,j;
int me = comm->me;
for (i = 1; i <= atom->ntypes; i++)
for (j = i; j <= atom->ntypes; j++) {
if (me == 0) fread(&setflag[i][j],sizeof(int),1,fp);
MPI_Bcast(&setflag[i][j],1,MPI_INT,0,world);
if (setflag[i][j]) {
if (me == 0) {
fread(&epsilon_read[i][j],sizeof(double),1,fp);
fread(&sigma_read[i][j],sizeof(double),1,fp);
fread(&cut_lj_read[i][j],sizeof(double),1,fp);
}
MPI_Bcast(&epsilon_read[i][j],1,MPI_DOUBLE,0,world);
MPI_Bcast(&sigma_read[i][j],1,MPI_DOUBLE,0,world);
MPI_Bcast(&cut_lj_read[i][j],1,MPI_DOUBLE,0,world);
}
}
}
/* ----------------------------------------------------------------------
proc 0 writes to restart file
------------------------------------------------------------------------- */
void PairLJLongDipoleLong::write_restart_settings(FILE *fp)
{
fwrite(&cut_lj_global,sizeof(double),1,fp);
fwrite(&cut_coul,sizeof(double),1,fp);
fwrite(&offset_flag,sizeof(int),1,fp);
fwrite(&mix_flag,sizeof(int),1,fp);
fwrite(&ewald_order,sizeof(int),1,fp);
}
/* ----------------------------------------------------------------------
proc 0 reads from restart file, bcasts
------------------------------------------------------------------------- */
void PairLJLongDipoleLong::read_restart_settings(FILE *fp)
{
if (comm->me == 0) {
fread(&cut_lj_global,sizeof(double),1,fp);
fread(&cut_coul,sizeof(double),1,fp);
fread(&offset_flag,sizeof(int),1,fp);
fread(&mix_flag,sizeof(int),1,fp);
fread(&ewald_order,sizeof(int),1,fp);
}
MPI_Bcast(&cut_lj_global,1,MPI_DOUBLE,0,world);
MPI_Bcast(&cut_coul,1,MPI_DOUBLE,0,world);
MPI_Bcast(&offset_flag,1,MPI_INT,0,world);
MPI_Bcast(&mix_flag,1,MPI_INT,0,world);
MPI_Bcast(&ewald_order,1,MPI_INT,0,world);
}
/* ----------------------------------------------------------------------
compute pair interactions
------------------------------------------------------------------------- */
void PairLJLongDipoleLong::compute(int eflag, int vflag)
{
double evdwl,ecoul,fpair;
evdwl = ecoul = 0.0;
if (eflag || vflag) ev_setup(eflag,vflag);
else evflag = vflag_fdotr = 0;
double **x = atom->x, *x0 = x[0];
double **mu = atom->mu, *mu0 = mu[0], *imu, *jmu;
double **tq = atom->torque, *tq0 = tq[0], *tqi;
double **f = atom->f, *f0 = f[0], *fi = f0, fx, fy, fz;
double *q = atom->q, qi = 0, qj;
int *type = atom->type;
int nlocal = atom->nlocal;
double *special_coul = force->special_coul;
double *special_lj = force->special_lj;
int newton_pair = force->newton_pair;
double qqrd2e = force->qqrd2e;
int i, j;
int order3 = ewald_order&(1<<3), order6 = ewald_order&(1<<6);
int *ineigh, *ineighn, *jneigh, *jneighn, typei, typej, ni;
double *cutsqi, *cut_ljsqi, *lj1i, *lj2i, *lj3i, *lj4i, *offseti;
double rsq, r2inv, force_coul, force_lj;
double g2 = g_ewald*g_ewald, g6 = g2*g2*g2, g8 = g6*g2;
double B0, B1, B2, B3, G0, G1, G2, mudi, mudj, muij;
vector force_d = VECTOR_NULL, ti = VECTOR_NULL, tj = VECTOR_NULL;
vector mui, muj, xi, d;
double C1 = 2.0 * g_ewald / MY_PIS;
double C2 = 2.0 * g2 * C1;
double C3 = 2.0 * g2 * C2;
ineighn = (ineigh = list->ilist)+list->inum;
for (; ineigh<ineighn; ++ineigh) { // loop over all neighs
i = *ineigh; fi = f0+3*i; tqi = tq0+3*i;
qi = q[i]; // initialize constants
offseti = offset[typei = type[i]];
lj1i = lj1[typei]; lj2i = lj2[typei]; lj3i = lj3[typei]; lj4i = lj4[typei];
cutsqi = cutsq[typei]; cut_ljsqi = cut_ljsq[typei];
memcpy(xi, x0+(i+(i<<1)), sizeof(vector));
memcpy(mui, imu = mu0+(i<<2), sizeof(vector));
jneighn = (jneigh = list->firstneigh[i])+list->numneigh[i];
for (; jneigh<jneighn; ++jneigh) { // loop over neighbors
j = *jneigh;
ni = sbmask(j); // special index
j &= NEIGHMASK;
{ register double *xj = x0+(j+(j<<1));
d[0] = xi[0] - xj[0]; // pair vector
d[1] = xi[1] - xj[1];
d[2] = xi[2] - xj[2]; }
if ((rsq = vec_dot(d, d)) >= cutsqi[typej = type[j]]) continue;
r2inv = 1.0/rsq;
if (order3 && (rsq < cut_coulsq)) { // dipole
memcpy(muj, jmu = mu0+(j<<2), sizeof(vector));
{ // series real space
register double r = sqrt(rsq);
register double x = g_ewald*r;
register double f = exp(-x*x)*qqrd2e;
B0 = 1.0/(1.0+EWALD_P*x); // eqn 2.8
B0 *= ((((A5*B0+A4)*B0+A3)*B0+A2)*B0+A1)*f/r;
B1 = (B0 + C1 * f) * r2inv;
B2 = (3.0*B1 + C2 * f) * r2inv;
B3 = (5.0*B2 + C3 * f) * r2inv;
mudi = mui[0]*d[0]+mui[1]*d[1]+mui[2]*d[2];
mudj = muj[0]*d[0]+muj[1]*d[1]+muj[2]*d[2];
muij = mui[0]*muj[0]+mui[1]*muj[1]+mui[2]*muj[2];
G0 = qi*(qj = q[j]); // eqn 2.10
G1 = qi*mudj-qj*mudi+muij;
G2 = -mudi*mudj;
force_coul = G0*B1+G1*B2+G2*B3;
mudi *= B2; mudj *= B2; // torque contribs
ti[0] = mudj*d[0]+(qj*d[0]-muj[0])*B1;
ti[1] = mudj*d[1]+(qj*d[1]-muj[1])*B1;
ti[2] = mudj*d[2]+(qj*d[2]-muj[2])*B1;
if (newton_pair || j < nlocal) {
tj[0] = mudi*d[0]-(qi*d[0]+mui[0])*B1;
tj[1] = mudi*d[1]-(qi*d[1]+mui[1])*B1;
tj[2] = mudi*d[2]-(qi*d[2]+mui[2])*B1;
}
if (eflag) ecoul = G0*B0+G1*B1+G2*B2;
if (ni > 0) { // adj part, eqn 2.13
force_coul -= (f = qqrd2e*(1.0-special_coul[ni])/r)*(
(3.0*G1+15.0*G2*r2inv)*r2inv+G0)*r2inv;
if (eflag)
ecoul -= f*((G1+3.0*G2*r2inv)*r2inv+G0);
B1 -= f*r2inv;
}
B0 = mudj+qj*B1; B3 = -qi*B1+mudi; // position independent
if (ni > 0) B0 -= f*3.0*mudj*r2inv*r2inv/B2;
if (ni > 0) B3 -= f*3.0*mudi*r2inv*r2inv/B2;
force_d[0] = B0*mui[0]+B3*muj[0]; // force contribs
force_d[1] = B0*mui[1]+B3*muj[1];
force_d[2] = B0*mui[2]+B3*muj[2];
if (ni > 0) {
ti[0] -= f*(3.0*mudj*r2inv*r2inv*d[0]/B2+(qj*r2inv*d[0]-muj[0]*r2inv));
ti[1] -= f*(3.0*mudj*r2inv*r2inv*d[1]/B2+(qj*r2inv*d[1]-muj[1]*r2inv));
ti[2] -= f*(3.0*mudj*r2inv*r2inv*d[2]/B2+(qj*r2inv*d[2]-muj[2]*r2inv));
if (newton_pair || j < nlocal) {
tj[0] -= f*(3.0*mudi*r2inv*r2inv*d[0]/B2-(qi*r2inv*d[0]+mui[0]*r2inv));
tj[1] -= f*(3.0*mudi*r2inv*r2inv*d[1]/B2-(qi*r2inv*d[1]+mui[1]*r2inv));
tj[2] -= f*(3.0*mudi*r2inv*r2inv*d[2]/B2-(qi*r2inv*d[2]+mui[2]*r2inv));
}
}
} // table real space
} else {
force_coul = ecoul = 0.0;
memset(force_d, 0, 3*sizeof(double));
}
if (rsq < cut_ljsqi[typej]) { // lj
if (order6) { // long-range lj
register double rn = r2inv*r2inv*r2inv;
register double x2 = g2*rsq, a2 = 1.0/x2;
x2 = a2*exp(-x2)*lj4i[typej];
if (ni < 0) {
force_lj =
(rn*=rn)*lj1i[typej]-g8*(((6.0*a2+6.0)*a2+3.0)*a2+1.0)*x2*rsq;
if (eflag) evdwl = rn*lj3i[typej]-g6*((a2+1.0)*a2+0.5)*x2;
}
else { // special case
register double f = special_lj[ni], t = rn*(1.0-f);
force_lj = f*(rn *= rn)*lj1i[typej]-
g8*(((6.0*a2+6.0)*a2+3.0)*a2+1.0)*x2*rsq+t*lj2i[typej];
if (eflag) evdwl =
f*rn*lj3i[typej]-g6*((a2+1.0)*a2+0.5)*x2+t*lj4i[typej];
}
}
else { // cut lj
register double rn = r2inv*r2inv*r2inv;
if (ni < 0) {
force_lj = rn*(rn*lj1i[typej]-lj2i[typej]);
if (eflag) evdwl = rn*(rn*lj3i[typej]-lj4i[typej])-offseti[typej];
}
else { // special case
register double f = special_lj[ni];
force_lj = f*rn*(rn*lj1i[typej]-lj2i[typej]);
if (eflag) evdwl = f*(
rn*(rn*lj3i[typej]-lj4i[typej])-offseti[typej]);
}
}
force_lj *= r2inv;
}
else force_lj = evdwl = 0.0;
fpair = force_coul+force_lj; // force
if (newton_pair || j < nlocal) {
register double *fj = f0+(j+(j<<1));
fi[0] += fx = d[0]*fpair+force_d[0]; fj[0] -= fx;
fi[1] += fy = d[1]*fpair+force_d[1]; fj[1] -= fy;
fi[2] += fz = d[2]*fpair+force_d[2]; fj[2] -= fz;
tqi[0] += mui[1]*ti[2]-mui[2]*ti[1]; // torque
tqi[1] += mui[2]*ti[0]-mui[0]*ti[2];
tqi[2] += mui[0]*ti[1]-mui[1]*ti[0];
register double *tqj = tq0+(j+(j<<1));
tqj[0] += muj[1]*tj[2]-muj[2]*tj[1];
tqj[1] += muj[2]*tj[0]-muj[0]*tj[2];
tqj[2] += muj[0]*tj[1]-muj[1]*tj[0];
}
else {
fi[0] += fx = d[0]*fpair+force_d[0]; // force
fi[1] += fy = d[1]*fpair+force_d[1];
fi[2] += fz = d[2]*fpair+force_d[2];
tqi[0] += mui[1]*ti[2]-mui[2]*ti[1]; // torque
tqi[1] += mui[2]*ti[0]-mui[0]*ti[2];
tqi[2] += mui[0]*ti[1]-mui[1]*ti[0];
}
if (evflag) ev_tally_xyz(i,j,nlocal,newton_pair,
evdwl,ecoul,fx,fy,fz,d[0],d[1],d[2]);
}
}
if (vflag_fdotr) virial_fdotr_compute();
}
/* ---------------------------------------------------------------------- */
/*
double PairLJLongDipoleLong::single(int i, int j, int itype, int jtype,
double rsq, double factor_coul, double factor_lj,
double &fforce)
{
double r6inv, force_coul, force_lj;
double g2 = g_ewald*g_ewald, g6 = g2*g2*g2, g8 = g6*g2, *q = atom->q;
double eng = 0.0;
double r2inv = 1.0/rsq;
if ((ewald_order&(1<<3)) && (rsq < cut_coulsq)) { // coulombic
double *mui = atom->mu[i], *muj = atom->mu[j];
double *xi = atom->x[i], *xj = atom->x[j];
double qi = q[i], qj = q[j];
double G0, G1, G2, B0, B1, B2, B3, mudi, mudj, muij;
vector d = {xi[0]-xj[0], xi[1]-xj[1], xi[2]-xj[2]};
{ // series real space
register double r = sqrt(rsq);
register double x = g_ewald*r;
register double f = exp(-x*x)*qqrd2e;
B0 = 1.0/(1.0+EWALD_P*x); // eqn 2.8
B0 *= ((((A5*B0+A4)*B0+A3)*B0+A2)*B0+A1)*f/r;
B1 = (B0 + C1 * f) * r2inv;
B2 = (3.0*B1 + C2 * f) * r2inv;
B3 = (5.0*B2 + C3 * f) * r2inv;
mudi = mui[0]*d[0]+mui[1]*d[1]+mui[2]*d[2];
mudj = muj[0]*d[0]+muj[1]*d[1]+muj[2]*d[2];
muij = mui[0]*muj[0]+mui[1]*muj[1]+mui[2]*muj[2];
G0 = qi*(qj = q[j]); // eqn 2.10
G1 = qi*mudj-qj*mudi+muij;
G2 = -mudi*mudj;
force_coul = G0*B1+G1*B2+G2*B3;
eng += G0*B0+G1*B1+G2*B2;
if (factor_coul < 1.0) { // adj part, eqn 2.13
force_coul -= (f = force->qqrd2e*(1.0-factor_coul)/r)*(
(3.0*G1+6.0*muij+15.0*G2*r2inv)*r2inv+G0);
eng -= f*((G1+3.0*G2*r2inv)*r2inv+G0);
B1 -= f*r2inv;
}
B0 = mudj*B2-qj*B1; B3 = qi*B1+mudi*B2; // position independent
//force_d[0] = B0*mui[0]+B3*muj[0]; // force contributions
//force_d[1] = B0*mui[1]+B3*muj[1];
//force_d[2] = B0*mui[2]+B3*muj[2];
} // table real space
}
else force_coul = 0.0;
if (rsq < cut_ljsq[itype][jtype]) { // lennard-jones
r6inv = r2inv*r2inv*r2inv;
if (ewald_order&0x40) { // long-range
register double x2 = g2*rsq, a2 = 1.0/x2, t = r6inv*(1.0-factor_lj);
x2 = a2*exp(-x2)*lj4[itype][jtype];
force_lj = factor_lj*(r6inv *= r6inv)*lj1[itype][jtype]-
g8*(((6.0*a2+6.0)*a2+3.0)*a2+a2)*x2*rsq+t*lj2[itype][jtype];
eng += factor_lj*r6inv*lj3[itype][jtype]-
g6*((a2+1.0)*a2+0.5)*x2+t*lj4[itype][jtype];
}
else { // cut
force_lj = factor_lj*r6inv*(lj1[itype][jtype]*r6inv-lj2[itype][jtype]);
eng += factor_lj*(r6inv*(r6inv*lj3[itype][jtype]-
lj4[itype][jtype])-offset[itype][jtype]);
}
}
else force_lj = 0.0;
fforce = (force_coul+force_lj)*r2inv;
return eng;
}
*/
Event Timeline
Log In to Comment