Files
lammps/src/npair_half_size_multi_newton_tri.cpp
2021-05-24 14:18:20 -04:00

141 lines
4.4 KiB
C++

// clang-format off
/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
https://www.lammps.org/, 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 "npair_half_size_multi_newton_tri.h"
#include "atom.h"
#include "error.h"
#include "my_page.h"
#include "neighbor.h"
#include "neigh_list.h"
using namespace LAMMPS_NS;
/* ---------------------------------------------------------------------- */
NPairHalfSizeMultiNewtonTri::NPairHalfSizeMultiNewtonTri(LAMMPS *lmp) : NPair(lmp) {}
/* ----------------------------------------------------------------------
size particles
binned neighbor list construction with Newton's 3rd law for triclinic
multi stencil is icollection-jcollection dependent
each owned atom i checks its own bin and other bins in triclinic stencil
every pair stored exactly once by some processor
------------------------------------------------------------------------- */
void NPairHalfSizeMultiNewtonTri::build(NeighList *list)
{
int i,j,k,n,itype,jtype,icollection,jcollection,ibin,jbin,ns,js;
double xtmp,ytmp,ztmp,delx,dely,delz,rsq;
double radi,radsum,cutdistsq;
int *neighptr,*s;
int *collection = neighbor->collection;
double **x = atom->x;
double *radius = atom->radius;
int *type = atom->type;
int *mask = atom->mask;
tagint *molecule = atom->molecule;
int nlocal = atom->nlocal;
if (includegroup) nlocal = atom->nfirst;
int history = list->history;
int *ilist = list->ilist;
int *numneigh = list->numneigh;
int **firstneigh = list->firstneigh;
MyPage<int> *ipage = list->ipage;
int mask_history = 3 << SBBITS;
int inum = 0;
ipage->reset();
for (i = 0; i < nlocal; i++) {
n = 0;
neighptr = ipage->vget();
itype = type[i];
icollection = collection[i];
xtmp = x[i][0];
ytmp = x[i][1];
ztmp = x[i][2];
radi = radius[i];
ibin = atom2bin[i];
// loop through stencils for all collections
for (jcollection = 0; jcollection < ncollections; jcollection++) {
// if same collection use own bin
if (icollection == jcollection) jbin = ibin;
else jbin = coord2bin(x[i], jcollection);
// loop over all atoms in bins in stencil
// stencil is empty if i larger than j
// stencil is half if i same size as j
// stencil is full if i smaller than j
// if half: pairs for atoms j "below" i are excluded
// below = lower z or (equal z and lower y) or (equal zy and lower x)
// (equal zyx and j <= i)
// latter excludes self-self interaction but allows superposed atoms
s = stencil_multi[icollection][jcollection];
ns = nstencil_multi[icollection][jcollection];
for (k = 0; k < ns; k++) {
js = binhead_multi[jcollection][jbin + s[k]];
for (j = js; j >= 0; j = bins[j]) {
// if same size (same collection), use half stencil
if (cutcollectionsq[icollection][icollection] == cutcollectionsq[jcollection][jcollection]){
if (x[j][2] < ztmp) continue;
if (x[j][2] == ztmp) {
if (x[j][1] < ytmp) continue;
if (x[j][1] == ytmp) {
if (x[j][0] < xtmp) continue;
if (x[j][0] == xtmp && j <= i) continue;
}
}
}
jtype = type[j];
if (exclude && exclusion(i,j,itype,jtype,mask,molecule)) continue;
delx = xtmp - x[j][0];
dely = ytmp - x[j][1];
delz = ztmp - x[j][2];
rsq = delx*delx + dely*dely + delz*delz;
radsum = radi + radius[j];
cutdistsq = (radsum+skin) * (radsum+skin);
if (rsq <= cutdistsq) {
if (history && rsq < radsum*radsum)
neighptr[n++] = j ^ mask_history;
else
neighptr[n++] = j;
}
}
}
}
ilist[inum++] = i;
firstneigh[i] = neighptr;
numneigh[i] = n;
ipage->vgot(n);
if (ipage->status())
error->one(FLERR,"Neighbor list overflow, boost neigh_modify one");
}
list->inum = inum;
}