Files
lammps/src/SNAP/compute_sna_grid.cpp
2021-07-02 17:47:45 -06:00

265 lines
7.5 KiB
C++

/* ----------------------------------------------------------------------
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.
------------------------------------------------------------------------- */
#include "compute_grid.h"
#include "compute_sna_grid.h"
#include <cstring>
#include <cstdlib>
#include "sna.h"
#include "atom.h"
#include "update.h"
#include "modify.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "neigh_request.h"
#include "force.h"
#include "pair.h"
#include "comm.h"
#include "memory.h"
#include "error.h"
using namespace LAMMPS_NS;
ComputeSNAGrid::ComputeSNAGrid(LAMMPS *lmp, int narg, char **arg) :
ComputeGrid(lmp, narg, arg), cutsq(NULL), sna(NULL),
radelem(NULL), wjelem(NULL)
{
double rmin0, rfac0;
int twojmax, switchflag, bzeroflag;
radelem = NULL;
wjelem = NULL;
// skip over arguments used by base class
// so that argument positions are identical to
// regular per-atom compute
arg += nargbase;
narg -= nargbase;
int ntypes = atom->ntypes;
int nargmin = 6+2*ntypes;
if (narg < nargmin) error->all(FLERR,"Illegal compute sna/grid command");
// default values
rmin0 = 0.0;
switchflag = 1;
bzeroflag = 1;
quadraticflag = 0;
// offset by 1 to match up with types
memory->create(radelem,ntypes+1,"sna/grid:radelem");
memory->create(wjelem,ntypes+1,"sna/grid:wjelem");
rcutfac = atof(arg[3]);
rfac0 = atof(arg[4]);
twojmax = atoi(arg[5]);
for(int i = 0; i < ntypes; i++)
radelem[i+1] = atof(arg[6+i]);
for(int i = 0; i < ntypes; i++)
wjelem[i+1] = atof(arg[6+ntypes+i]);
// construct cutsq
double cut;
cutmax = 0.0;
memory->create(cutsq,ntypes+1,ntypes+1,"sna/grid:cutsq");
for(int i = 1; i <= ntypes; i++) {
cut = 2.0*radelem[i]*rcutfac;
if (cut > cutmax) cutmax = cut;
cutsq[i][i] = cut*cut;
for(int j = i+1; j <= ntypes; j++) {
cut = (radelem[i]+radelem[j])*rcutfac;
cutsq[i][j] = cutsq[j][i] = cut*cut;
}
}
// process optional args
int iarg = nargmin;
while (iarg < narg) {
if (strcmp(arg[iarg],"rmin0") == 0) {
if (iarg+2 > narg)
error->all(FLERR,"Illegal compute sna/grid command");
rmin0 = atof(arg[iarg+1]);
iarg += 2;
} else if (strcmp(arg[iarg],"switchflag") == 0) {
if (iarg+2 > narg)
error->all(FLERR,"Illegal compute sna/grid command");
switchflag = atoi(arg[iarg+1]);
iarg += 2;
} else if (strcmp(arg[iarg],"bzeroflag") == 0) {
if (iarg+2 > narg)
error->all(FLERR,"Illegal compute sna/grid command");
bzeroflag = atoi(arg[iarg+1]);
iarg += 2;
} else if (strcmp(arg[iarg],"quadraticflag") == 0) {
if (iarg+2 > narg)
error->all(FLERR,"Illegal compute sna/grid command");
quadraticflag = atoi(arg[iarg+1]);
iarg += 2;
} else error->all(FLERR,"Illegal compute sna/grid command");
}
snaptr = new SNA(lmp,rfac0,twojmax,
rmin0,switchflag,bzeroflag);
ncoeff = snaptr->ncoeff;
nvalues = ncoeff;
if (quadraticflag) nvalues += (ncoeff*(ncoeff+1))/2;
size_array_cols = size_array_cols_base + nvalues;
array_flag = 1;
}
/* ---------------------------------------------------------------------- */
ComputeSNAGrid::~ComputeSNAGrid()
{
memory->destroy(sna);
memory->destroy(radelem);
memory->destroy(wjelem);
memory->destroy(cutsq);
delete snaptr;
}
/* ---------------------------------------------------------------------- */
void ComputeSNAGrid::init()
{
if (force->pair == NULL)
error->all(FLERR,"Compute sna/grid requires a pair style be defined");
if (cutmax > force->pair->cutforce)
error->all(FLERR,"Compute sna/grid cutoff is longer than pairwise cutoff");
// need an occasional full neighbor list
int irequest = neighbor->request(this,instance_me);
neighbor->requests[irequest]->pair = 0;
neighbor->requests[irequest]->compute = 1;
neighbor->requests[irequest]->half = 0;
neighbor->requests[irequest]->full = 1;
neighbor->requests[irequest]->occasional = 1;
int count = 0;
for (int i = 0; i < modify->ncompute; i++)
if (strcmp(modify->compute[i]->style,"sna/grid") == 0) count++;
if (count > 1 && comm->me == 0)
error->warning(FLERR,"More than one compute sna/grid");
snaptr->init();
}
/* ---------------------------------------------------------------------- */
void ComputeSNAGrid::compute_array()
{
invoked_array = update->ntimestep;
int * const type = atom->type;
// compute sna for each gridpoint
double** const x = atom->x;
const int* const mask = atom->mask;
const int ntotal = atom->nlocal + atom->nghost;
// insure rij, inside, and typej are of size jnum
snaptr->grow_rij(ntotal);
for (int iz = nzlo; iz <= nzhi; iz++)
for (int iy = nylo; iy <= nyhi; iy++)
for (int ix = nxlo; ix <= nxhi; ix++) {
const int igrid = iz*(nx*ny) + iy*nx + ix;
const double xtmp = grid[igrid][0];
const double ytmp = grid[igrid][1];
const double ztmp = grid[igrid][2];
// rij[][3] = displacements between atom I and those neighbors
// inside = indices of neighbors of I within cutoff
// typej = types of neighbors of I within cutoff
int ninside = 0;
for (int j = 0; j < ntotal; j++) {
// check that j is in compute group
if (!(mask[j] & groupbit)) continue;
const double delx = xtmp - x[j][0];
const double dely = ytmp - x[j][1];
const double delz = ztmp - x[j][2];
const double rsq = delx*delx + dely*dely + delz*delz;
int jtype = type[j];
if (rsq < cutsq[jtype][jtype] && rsq>1e-20) {
snaptr->rij[ninside][0] = delx;
snaptr->rij[ninside][1] = dely;
snaptr->rij[ninside][2] = delz;
snaptr->inside[ninside] = j;
snaptr->wj[ninside] = wjelem[jtype];
snaptr->rcutij[ninside] = 2.0*radelem[jtype]*rcutfac;
ninside++;
}
}
snaptr->compute_ui(ninside);
snaptr->compute_zi();
snaptr->compute_bi();
for (int icoeff = 0; icoeff < ncoeff; icoeff++)
gridlocal[size_array_cols_base+icoeff][iz][iy][ix] = snaptr->blist[icoeff];
if (quadraticflag) {
int ncount = ncoeff;
for (int icoeff = 0; icoeff < ncoeff; icoeff++) {
double bi = snaptr->blist[icoeff];
// diagonal element of quadratic matrix
gridlocal[size_array_cols_base+ncount++][iz][iy][ix] = 0.5*bi*bi;
// upper-triangular elements of quadratic matrix
for (int jcoeff = icoeff+1; jcoeff < ncoeff; jcoeff++)
gridlocal[size_array_cols_base+ncount++][iz][iy][ix] = bi*snaptr->blist[jcoeff];
}
}
}
for (int iz = nzlo; iz <= nzhi; iz++)
for (int iy = nylo; iy <= nyhi; iy++)
for (int ix = nxlo; ix <= nxhi; ix++) {
const int igrid = iz*(nx*ny) + iy*nx + ix;
for (int j = 0; j < nvalues; j++)
grid[igrid][size_array_cols_base + j] = gridlocal[size_array_cols_base + j][iz][iy][ix];
}
MPI_Allreduce(&grid[0][0],&gridall[0][0],ngrid*size_array_cols,MPI_DOUBLE,MPI_SUM,world);
}
/* ----------------------------------------------------------------------
memory usage
------------------------------------------------------------------------- */
double ComputeSNAGrid::memory_usage()
{
double nbytes = snaptr->memory_usage(); // SNA object
return nbytes;
}