Files
lammps/src/compute_centro_atom.cpp
2023-09-18 16:51:19 -04:00

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C++

/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
https://www.lammps.org/, Sandia National Laboratories
LAMMPS development team: developers@lammps.org
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: Michel Perez (U Lyon) for non-fcc lattices
------------------------------------------------------------------------- */
#include "compute_centro_atom.h"
#include "atom.h"
#include "comm.h"
#include "error.h"
#include "force.h"
#include "math_extra.h"
#include "memory.h"
#include "modify.h"
#include "neigh_list.h"
#include "neighbor.h"
#include "pair.h"
#include "update.h"
#include <cstring>
#include <utility>
using namespace LAMMPS_NS;
/* ---------------------------------------------------------------------- */
ComputeCentroAtom::ComputeCentroAtom(LAMMPS *lmp, int narg, char **arg) :
Compute(lmp, narg, arg), distsq(nullptr), nearest(nullptr), centro(nullptr)
{
if (narg < 4 || narg > 6) error->all(FLERR, "Illegal compute centro/atom command");
if (strcmp(arg[3], "fcc") == 0)
nnn = 12;
else if (strcmp(arg[3], "bcc") == 0)
nnn = 8;
else
nnn = utils::inumeric(FLERR, arg[3], false, lmp);
// default values
axes_flag = 0;
// optional keywords
int iarg = 4;
while (iarg < narg) {
if (strcmp(arg[iarg], "axes") == 0) {
if (iarg + 2 > narg) error->all(FLERR, "Illegal compute centro/atom command3");
axes_flag = utils::logical(FLERR, arg[iarg + 1], false, lmp);
iarg += 2;
} else
error->all(FLERR, "Illegal compute centro/atom command1");
}
if (nnn <= 0 || nnn % 2)
error->all(FLERR, "Illegal neighbor value for compute centro/atom command");
peratom_flag = 1;
if (!axes_flag)
size_peratom_cols = 0;
else
size_peratom_cols = 10;
nmax = 0;
maxneigh = 0;
}
/* ---------------------------------------------------------------------- */
ComputeCentroAtom::~ComputeCentroAtom()
{
memory->destroy(centro);
memory->destroy(distsq);
memory->destroy(nearest);
if (axes_flag) memory->destroy(array_atom);
}
/* ---------------------------------------------------------------------- */
void ComputeCentroAtom::init()
{
if (force->pair == nullptr)
error->all(FLERR, "Compute centro/atom requires a pair style be defined");
// need an occasional full neighbor list
neighbor->add_request(this, NeighConst::REQ_FULL | NeighConst::REQ_OCCASIONAL);
if (modify->get_compute_by_style(style).size() > 1)
if (comm->me == 0) error->warning(FLERR, "More than one compute {}", style);
}
/* ---------------------------------------------------------------------- */
void ComputeCentroAtom::init_list(int /*id*/, NeighList *ptr)
{
list = ptr;
}
/* ---------------------------------------------------------------------- */
void ComputeCentroAtom::compute_peratom()
{
int i, j, k, ii, jj, kk, n, inum, jnum;
double xtmp, ytmp, ztmp, delx, dely, delz, rsq, value;
int *ilist, *jlist, *numneigh, **firstneigh;
invoked_peratom = update->ntimestep;
// grow centro array if necessary
// grow array_atom array if axes_flag set
if (atom->nmax > nmax) {
if (!axes_flag) {
memory->destroy(centro);
nmax = atom->nmax;
memory->create(centro, nmax, "centro/atom:centro");
vector_atom = centro;
} else {
memory->destroy(centro);
memory->destroy(array_atom);
nmax = atom->nmax;
memory->create(centro, nmax, "centro/atom:centro");
memory->create(array_atom, nmax, size_peratom_cols, "centro/atom:array_atom");
}
}
// invoke full neighbor list (will copy or build if necessary)
neighbor->build_one(list);
inum = list->inum;
ilist = list->ilist;
numneigh = list->numneigh;
firstneigh = list->firstneigh;
// npairs = number of unique pairs
int nhalf = nnn / 2;
int npairs = nnn * (nnn - 1) / 2;
auto pairs = new double[npairs];
// compute centro-symmetry parameter for each atom in group
// use full neighbor list
double **x = atom->x;
int *mask = atom->mask;
double cutsq = force->pair->cutforce * force->pair->cutforce;
for (ii = 0; ii < inum; ii++) {
i = ilist[ii];
if (mask[i] & groupbit) {
xtmp = x[i][0];
ytmp = x[i][1];
ztmp = x[i][2];
jlist = firstneigh[i];
jnum = numneigh[i];
// ensure distsq and nearest arrays are long enough
if (jnum > maxneigh) {
memory->destroy(distsq);
memory->destroy(nearest);
maxneigh = jnum;
memory->create(distsq, maxneigh, "centro/atom:distsq");
memory->create(nearest, maxneigh, "centro/atom:nearest");
}
// loop over list of all neighbors within force cutoff
// distsq[] = distance sq to each
// nearest[] = atom indices of neighbors
n = 0;
for (jj = 0; jj < jnum; jj++) {
j = jlist[jj];
j &= NEIGHMASK;
delx = xtmp - x[j][0];
dely = ytmp - x[j][1];
delz = ztmp - x[j][2];
rsq = delx * delx + dely * dely + delz * delz;
if (rsq < cutsq) {
distsq[n] = rsq;
nearest[n++] = j;
}
}
// check whether to include local crystal symmetry axes
if (!axes_flag) {
// if not nnn neighbors, centro = 0.0
if (n < nnn) {
centro[i] = 0.0;
continue;
}
// store nnn nearest neighs in 1st nnn locations of distsq and nearest
select2(nnn, n, distsq, nearest);
// R = Ri + Rj for each of npairs i,j pairs among nnn neighbors
// pairs = squared length of each R
n = 0;
for (j = 0; j < nnn; j++) {
jj = nearest[j];
for (k = j + 1; k < nnn; k++) {
kk = nearest[k];
delx = x[jj][0] + x[kk][0] - 2.0 * xtmp;
dely = x[jj][1] + x[kk][1] - 2.0 * ytmp;
delz = x[jj][2] + x[kk][2] - 2.0 * ztmp;
pairs[n++] = delx * delx + dely * dely + delz * delz;
}
}
} else {
// calculate local crystal symmetry axes
// rsq1, rsq2 are two smallest values of R^2
// R1, R2 are corresponding vectors Ri - Rj
// R3 is normal to R1, R2
double rsq1, rsq2;
double *r1 = &array_atom[i][1];
double *r2 = &array_atom[i][4];
double *r3 = &array_atom[i][7];
if (n < nnn) {
centro[i] = 0.0;
MathExtra::zero3(r1);
MathExtra::zero3(r2);
MathExtra::zero3(r3);
continue;
}
// store nnn nearest neighs in 1st nnn locations of distsq and nearest
select2(nnn, n, distsq, nearest);
n = 0;
rsq1 = rsq2 = cutsq;
for (j = 0; j < nnn; j++) {
jj = nearest[j];
for (k = j + 1; k < nnn; k++) {
kk = nearest[k];
delx = x[jj][0] + x[kk][0] - 2.0 * xtmp;
dely = x[jj][1] + x[kk][1] - 2.0 * ytmp;
delz = x[jj][2] + x[kk][2] - 2.0 * ztmp;
rsq = delx * delx + dely * dely + delz * delz;
pairs[n++] = rsq;
if (rsq < rsq2) {
if (rsq < rsq1) {
rsq2 = rsq1;
MathExtra::copy3(r1, r2);
rsq1 = rsq;
MathExtra::sub3(x[jj], x[kk], r1);
} else {
rsq2 = rsq;
MathExtra::sub3(x[jj], x[kk], r2);
}
}
}
}
MathExtra::cross3(r1, r2, r3);
MathExtra::norm3(r1);
MathExtra::norm3(r2);
MathExtra::norm3(r3);
}
// store nhalf smallest pair distances in 1st nhalf locations of pairs
select(nhalf, npairs, pairs);
// centrosymmetry = sum of nhalf smallest squared values
value = 0.0;
for (j = 0; j < nhalf; j++) value += pairs[j];
centro[i] = value;
} else {
centro[i] = 0.0;
if (axes_flag) {
MathExtra::zero3(&array_atom[i][1]);
MathExtra::zero3(&array_atom[i][4]);
MathExtra::zero3(&array_atom[i][7]);
}
}
}
delete[] pairs;
if (axes_flag)
for (ii = 0; ii < inum; ii++) {
i = ilist[ii];
if (mask[i] & groupbit) array_atom[i][0] = centro[i];
}
}
/* ----------------------------------------------------------------------
2 select routines from Numerical Recipes (slightly modified)
find k smallest values in array of length n
2nd routine sorts auxiliary array at same time
------------------------------------------------------------------------- */
void ComputeCentroAtom::select(int k, int n, double *arr)
{
int i, ir, j, l, mid;
double a;
arr--;
l = 1;
ir = n;
while (true) {
if (ir <= l + 1) {
if (ir == l + 1 && arr[ir] < arr[l]) std::swap(arr[l], arr[ir]);
return;
} else {
mid = (l + ir) >> 1;
std::swap(arr[mid], arr[l + 1]);
if (arr[l] > arr[ir]) std::swap(arr[l], arr[ir]);
if (arr[l + 1] > arr[ir]) std::swap(arr[l + 1], arr[ir]);
if (arr[l] > arr[l + 1]) std::swap(arr[l], arr[l + 1]);
i = l + 1;
j = ir;
a = arr[l + 1];
while (true) {
do i++;
while (arr[i] < a);
do j--;
while (arr[j] > a);
if (j < i) break;
std::swap(arr[i], arr[j]);
}
arr[l + 1] = arr[j];
arr[j] = a;
if (j >= k) ir = j - 1;
if (j <= k) l = i;
}
}
}
/* ---------------------------------------------------------------------- */
void ComputeCentroAtom::select2(int k, int n, double *arr, int *iarr)
{
int i, ir, j, l, mid, ia;
double a;
arr--;
iarr--;
l = 1;
ir = n;
while (true) {
if (ir <= l + 1) {
if (ir == l + 1 && arr[ir] < arr[l]) {
std::swap(arr[l], arr[ir]);
std::swap(iarr[l], iarr[ir]);
}
return;
} else {
mid = (l + ir) >> 1;
std::swap(arr[mid], arr[l + 1]);
std::swap(iarr[mid], iarr[l + 1]);
if (arr[l] > arr[ir]) {
std::swap(arr[l], arr[ir]);
std::swap(iarr[l], iarr[ir]);
}
if (arr[l + 1] > arr[ir]) {
std::swap(arr[l + 1], arr[ir]);
std::swap(iarr[l + 1], iarr[ir]);
}
if (arr[l] > arr[l + 1]) {
std::swap(arr[l], arr[l + 1]);
std::swap(iarr[l], iarr[l + 1]);
}
i = l + 1;
j = ir;
a = arr[l + 1];
ia = iarr[l + 1];
while (true) {
do i++;
while (arr[i] < a);
do j--;
while (arr[j] > a);
if (j < i) break;
std::swap(arr[i], arr[j]);
std::swap(iarr[i], iarr[j]);
}
arr[l + 1] = arr[j];
arr[j] = a;
iarr[l + 1] = iarr[j];
iarr[j] = ia;
if (j >= k) ir = j - 1;
if (j <= k) l = i;
}
}
}
/* ----------------------------------------------------------------------
memory usage of local atom-based array
------------------------------------------------------------------------- */
double ComputeCentroAtom::memory_usage()
{
double bytes = (double) nmax * sizeof(double);
if (axes_flag) bytes += (double) size_peratom_cols * nmax * sizeof(double);
return bytes;
}