Commit1 JT 082118

- created pppm_dipole_spin.h/cpp (child-class of pppm_dipole)
- improved pair_spin_long.h/cpp
- created documentation for pair_spin_long
- new 3xN fm_long vector in atom_vec_spin (with associated comm)
This commit is contained in:
julient31 2018-08-21 13:47:38 -06:00
parent 5e287033f7
commit 8d79db03d3
16 changed files with 1839 additions and 751 deletions

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\documentclass[preview]{standalone}
\usepackage{varwidth}
\usepackage[utf8x]{inputenc}
\usepackage{amsmath,amssymb,graphics,bm,setspace}
\begin{document}
\begin{varwidth}{50in}
\begin{equation}
\mathcal{H}_{\rm long}=
-\frac{\mu_{0} \left( \mu_B\right)^2}{4\pi}
\sum_{i,j,i\neq j}^{N}
\frac{g_i g_j}{r_{ij}^3}
\Big(3
\left(\bm{e}_{ij}\cdot \bm{s}_{i}\right)
\left(\bm{e}_{ij}\cdot \bm{s}_{j}\right)
-\bm{s}_i\cdot\bm{s}_j \Big)
\nonumber
\end{equation}
\end{varwidth}
\end{document}

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\documentclass[preview]{standalone}
\usepackage{varwidth}
\usepackage[utf8x]{inputenc}
\usepackage{amsmath,amssymb,graphics,bm,setspace}
\begin{document}
\begin{varwidth}{50in}
\begin{equation}
\bm{F}_i =
\frac{\mu_0 (\mu_B)^2}{4\pi} \sum_j
\frac{g_i g_j}{r_{ij}^4}
\Big[\big( (\bm{s}_i\cdot\bm{s}_j)
-5(\bm{e}_{ij}\cdot\bm{s}_i)
(\bm{e}_{ij}\cdot\bm{s}_j)\big) \bm{e}_{ij}+
\big(
(\bm{e}_{ij}\cdot\bm{s}_i)\bm{s}_j+
(\bm{e}_{ij}\cdot\bm{s}_j)\bm{s}_i
\big)
\Big]
\nonumber
\end{equation}
\end{varwidth}
\end{document}

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\documentclass[preview]{standalone}
\usepackage{varwidth}
\usepackage[utf8x]{inputenc}
\usepackage{amsmath,amssymb,graphics,bm,setspace}
\begin{document}
\begin{varwidth}{50in}
\begin{equation}
\bm{\omega}_i =
\frac{\mu_0 (\mu_B)^2}{4\pi\hbar}\sum_{j}
\frac{g_i g_j}{r_{ij}^3}
\, \Big(
3\,(\bm{e}_{ij}\cdot\bm{s}_{j})\bm{e}_{ij}
-\bm{s}_{j} \Big) \nonumber
\end{equation}
\end{varwidth}
\end{document}

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"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Commands_all.html)
:line
pair_style spin/long command :h3
[Syntax:]
pair_style spin/long cutoff (cutoff)
cutoff = global cutoff pair (distance in metal units) :ulb,l
:ule
[Examples:]
pair_style spin/long 10.0
pair_coeff * * long 10.0
pair_coeff 2 3 long 8.0 :pre
[Description:]
Style {pair/spin/long} computes interactions between pairs of particles
that each have a magnetic spin.
:c,image(Eqs/pair_spin_long_range.jpg)
where si and sj are two magnetic spins of two particles with Lande factors
gi and gj respectively, eij = (ri - rj)/|ri-rj| is the unit vector between
sites i and j, mu0 the vacuum permeability, muB the Bohr magneton (muB =
5.788 eV/T in metal units).
Style {pair/spin/long} computes magnetic precession vectors:
:c,image(Eqs/pair_spin_long_range_magforce.jpg)
with h the Planck constant (in metal units), and a mechanical force:
:c,image(Eqs/pair_spin_long_range_force.jpg)
The following coefficient must be defined for each pair of atoms
types via the "pair_coeff"_pair_coeff.html command as in the examples
above, or in the data file or restart files read by the
"read_data"_read_data.html or "read_restart"_read_restart.html
commands, or by mixing as described below:
rc (distance units) :ul
with rc is the radius cutoff of the short-range component of the
long-range interaction (see "(Cerda)"_#Cerda1 for more
explanation).
:line
[Restrictions:]
The {pair/spin/long} style is part of the SPIN package. It is only
enabled if LAMMPS was built with that package. See the
"Making LAMMPS"_Section_start.html#start_3 section for more info.
The {pair/spin/long} style computes the short-range component of
the dipole-dipole interaction. The functions evaluating the
long-range component are part of the KSPACE package.
They can be enabled only if LAMMPS was built with that package.
[Related commands:]
"atom_style spin"_atom_style.html, "pair_coeff"_pair_coeff.html,
[Default:] none
:line
:link(Tranchida6)
[(Tranchida)] Tranchida, Plimpton, Thibaudeau and Thompson,
Journal of Computational Physics, (2018).
:link(Cerda1)
[(Cerda)] Cerda, Ballenegger, Lenz, and Holm, J Chem Phys, 129(23),
234104 (2008).

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213
src/KSPACE/pppm_dipole.h Normal file
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/* -*- 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.
------------------------------------------------------------------------- */
#ifdef KSPACE_CLASS
KSpaceStyle(pppm/dipole,PPPMDipole)
#else
#ifndef LMP_PPPM_DIPOLE_H
#define LMP_PPPM_DIPOLE_H
#include "pppm.h"
namespace LAMMPS_NS {
class PPPMDipole : public PPPM {
public:
PPPMDipole(class LAMMPS *, int, char **);
virtual ~PPPMDipole();
void init();
void setup();
void setup_grid();
void compute(int, int);
int timing_1d(int, double &);
int timing_3d(int, double &);
double memory_usage();
protected:
void set_grid_global(double);
//double newton_raphson_f();
void allocate();
void allocate_peratom();
void deallocate();
void deallocate_peratom();
void compute_gf_denom();
void slabcorr();
// grid communication
void pack_forward(int, FFT_SCALAR *, int, int *);
void unpack_forward(int, FFT_SCALAR *, int, int *);
void pack_reverse(int, FFT_SCALAR *, int, int *);
void unpack_reverse(int, FFT_SCALAR *, int, int *);
// dipole
FFT_SCALAR ***densityx_brick_dipole,***densityy_brick_dipole,***densityz_brick_dipole;
FFT_SCALAR ***vdxx_brick_dipole,***vdyy_brick_dipole,***vdzz_brick_dipole;
FFT_SCALAR ***vdxy_brick_dipole,***vdxz_brick_dipole,***vdyz_brick_dipole;
FFT_SCALAR ***ux_brick_dipole,***uy_brick_dipole,***uz_brick_dipole;
FFT_SCALAR ***v0x_brick_dipole,***v1x_brick_dipole,***v2x_brick_dipole;
FFT_SCALAR ***v3x_brick_dipole,***v4x_brick_dipole,***v5x_brick_dipole;
FFT_SCALAR ***v0y_brick_dipole,***v1y_brick_dipole,***v2y_brick_dipole;
FFT_SCALAR ***v3y_brick_dipole,***v4y_brick_dipole,***v5y_brick_dipole;
FFT_SCALAR ***v0z_brick_dipole,***v1z_brick_dipole,***v2z_brick_dipole;
FFT_SCALAR ***v3z_brick_dipole,***v4z_brick_dipole,***v5z_brick_dipole;
FFT_SCALAR *work3,*work4;
FFT_SCALAR *densityx_fft_dipole,*densityy_fft_dipole,*densityz_fft_dipole;
class GridComm *cg_dipole;
class GridComm *cg_peratom_dipole;
int only_dipole_flag;
double musum,musqsum,mu2;
double find_gewald_dipole(double, double, bigint, double, double);
double newton_raphson_f_dipole(double, double, bigint, double, double);
double derivf_dipole(double, double, bigint, double, double);
double compute_df_kspace_dipole(double);
double compute_qopt_dipole();
void compute_gf_dipole();
void make_rho_dipole();
void brick2fft_dipole();
void poisson_ik_dipole();
void poisson_peratom_dipole();
void fieldforce_ik_dipole();
void fieldforce_peratom_dipole();
double final_accuracy_dipole(double dipole2);
void musum_musq();
};
}
#endif
#endif
/* ERROR/WARNING messages:
E: Cannot (yet) use charges with Kspace style PPPMDipole
Charge-dipole interactions are not yet implemented in PPPMDipole so this
feature is not yet supported.
E: Must redefine kspace_style after changing to triclinic box
Self-explanatory.
E: Kspace style requires atom attribute mu
The atom style defined does not have this attribute.
E: Cannot (yet) use kspace_modify diff ad with dipoles
This feature is not yet supported.
E: Cannot (yet) use 'electron' units with dipoles
This feature is not yet supported.
E: Cannot yet use triclinic cells with PPPMDipole
This feature is not yet supported.
E: Cannot yet use TIP4P with PPPMDipole
This feature is not yet supported.
E: Cannot use nonperiodic boundaries with PPPM
For kspace style pppm, all 3 dimensions must have periodic boundaries
unless you use the kspace_modify command to define a 2d slab with a
non-periodic z dimension.
E: Incorrect boundaries with slab PPPM
Must have periodic x,y dimensions and non-periodic z dimension to use
2d slab option with PPPM.
E: PPPM order cannot be < 2 or > than %d
This is a limitation of the PPPM implementation in LAMMPS.
E: KSpace style is incompatible with Pair style
Setting a kspace style requires that a pair style with matching
long-range dipole components be used.
W: Reducing PPPM order b/c stencil extends beyond nearest neighbor processor
This may lead to a larger grid than desired. See the kspace_modify overlap
command to prevent changing of the PPPM order.
E: PPPM order < minimum allowed order
The default minimum order is 2. This can be reset by the
kspace_modify minorder command.
E: PPPM grid stencil extends beyond nearest neighbor processor
This is not allowed if the kspace_modify overlap setting is no.
E: KSpace accuracy must be > 0
The kspace accuracy designated in the input must be greater than zero.
E: Could not compute grid size
The code is unable to compute a grid size consistent with the desired
accuracy. This error should not occur for typical problems. Please
send an email to the developers.
E: PPPM grid is too large
The global PPPM grid is larger than OFFSET in one or more dimensions.
OFFSET is currently set to 4096. You likely need to decrease the
requested accuracy.
E: Could not compute g_ewald
The Newton-Raphson solver failed to converge to a good value for
g_ewald. This error should not occur for typical problems. Please
send an email to the developers.
E: Non-numeric box dimensions - simulation unstable
The box size has apparently blown up.
E: Out of range atoms - cannot compute PPPM
One or more atoms are attempting to map their charge to a PPPM grid
point that is not owned by a processor. This is likely for one of two
reasons, both of them bad. First, it may mean that an atom near the
boundary of a processor's sub-domain has moved more than 1/2 the
"neighbor skin distance"_neighbor.html without neighbor lists being
rebuilt and atoms being migrated to new processors. This also means
you may be missing pairwise interactions that need to be computed.
The solution is to change the re-neighboring criteria via the
"neigh_modify"_neigh_modify command. The safest settings are "delay 0
every 1 check yes". Second, it may mean that an atom has moved far
outside a processor's sub-domain or even the entire simulation box.
This indicates bad physics, e.g. due to highly overlapping atoms, too
large a timestep, etc.
E: Using kspace solver PPPMDipole on system with no dipoles
Must have non-zero dipoles with PPPMDipole.
E: Must use kspace_modify gewald for system with no dipoles
Self-explanatory.
*/

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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: Stan Moore (SNL)
Julien Tranchida (SNL)
------------------------------------------------------------------------- */
#include <mpi.h>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include "pppm_dipole_spin.h"
#include "atom.h"
#include "comm.h"
#include "gridcomm.h"
#include "neighbor.h"
#include "force.h"
#include "pair.h"
#include "bond.h"
#include "angle.h"
#include "domain.h"
#include "fft3d_wrap.h"
#include "remap_wrap.h"
#include "memory.h"
#include "error.h"
#include "update.h"
#include "math_const.h"
#include "math_special.h"
using namespace LAMMPS_NS;
using namespace MathConst;
using namespace MathSpecial;
#define MAXORDER 7
#define OFFSET 16384
#define LARGE 10000.0
#define SMALL 0.00001
#define EPS_HOC 1.0e-7
enum{REVERSE_SP};
enum{FORWARD_SP,FORWARD_SP_PERATOM};
#ifdef FFT_SINGLE
#define ZEROF 0.0f
#define ONEF 1.0f
#else
#define ZEROF 0.0
#define ONEF 1.0
#endif
/* ---------------------------------------------------------------------- */
PPPMDipoleSpin::PPPMDipoleSpin(LAMMPS *lmp, int narg, char **arg) :
PPPMDipole(lmp, narg, arg)
{
dipoleflag = 0;
spinflag = 1;
group_group_enable = 0;
cg_dipole = NULL;
cg_peratom_dipole = NULL;
}
/* ----------------------------------------------------------------------
free all memory
------------------------------------------------------------------------- */
PPPMDipoleSpin::~PPPMDipoleSpin()
{
if (copymode) return;
deallocate();
if (peratom_allocate_flag) deallocate_peratom();
fft1 = NULL;
fft2 = NULL;
remap = NULL;
cg_dipole = NULL;
}
/* ----------------------------------------------------------------------
called once before run
------------------------------------------------------------------------- */
void PPPMDipoleSpin::init()
{
if (me == 0) {
if (screen) fprintf(screen,"PPPMDipoleSpin initialization ...\n");
if (logfile) fprintf(logfile,"PPPMDipoleSpin initialization ...\n");
}
// error check
spinflag = atom->sp?1:0;
triclinic_check();
if (triclinic != domain->triclinic)
error->all(FLERR,"Must redefine kspace_style after changing to triclinic box");
if (domain->dimension == 2) error->all(FLERR,
"Cannot use PPPMDipoleSpin with 2d simulation");
if (comm->style != 0)
error->universe_all(FLERR,"PPPMDipoleSpin can only currently be used with "
"comm_style brick");
if (!atom->sp) error->all(FLERR,"Kspace style requires atom attribute sp");
if (atom->sp && differentiation_flag == 1) error->all(FLERR,"Cannot (yet) use kspace_modify diff"
" ad with spins");
if (spinflag && strcmp(update->unit_style,"metal") != 0)
error->all(FLERR,"'metal' units have to be used with spins");
if (slabflag == 0 && domain->nonperiodic > 0)
error->all(FLERR,"Cannot use nonperiodic boundaries with PPPMDipoleSpin");
if (slabflag) {
if (domain->xperiodic != 1 || domain->yperiodic != 1 ||
domain->boundary[2][0] != 1 || domain->boundary[2][1] != 1)
error->all(FLERR,"Incorrect boundaries with slab PPPMDipoleSpin");
}
if (order < 2 || order > MAXORDER) {
char str[128];
sprintf(str,"PPPMDipoleSpin order cannot be < 2 or > than %d",MAXORDER);
error->all(FLERR,str);
}
// extract short-range Coulombic cutoff from pair style
triclinic = domain->triclinic;
if (triclinic)
error->all(FLERR,"Cannot yet use triclinic cells with PPPMDipoleSpin");
pair_check();
int itmp = 0;
double *p_cutoff = (double *) force->pair->extract("cut_coul",itmp);
if (p_cutoff == NULL)
error->all(FLERR,"KSpace style is incompatible with Pair style");
cutoff = *p_cutoff;
// kspace TIP4P not yet supported
if (tip4pflag)
error->all(FLERR,"Cannot yet use TIP4P with PPPMDipoleSpin");
scale = 1.0;
hbar = force->hplanck/MY_2PI; // eV/(rad.THz)
mub = 5.78901e-5; // in eV/T
mu_0 = 1.2566370614e-6; // in T.m/A
mub2mu0 = mub * mub * mu_0; // in eV
mub2mu0hbinv = mub2mu0 / hbar; // in rad.THz
spsum_spsq();
natoms_original = atom->natoms;
// set accuracy (force units) from accuracy_relative or accuracy_absolute
// is two_charge_force still relevant for spin systems?
if (accuracy_absolute >= 0.0) accuracy = accuracy_absolute;
else accuracy = accuracy_relative * two_charge_force;
// free all arrays previously allocated
deallocate();
if (peratom_allocate_flag) deallocate_peratom();
// setup FFT grid resolution and g_ewald
// normally one iteration thru while loop is all that is required
// if grid stencil does not extend beyond neighbor proc
// or overlap is allowed, then done
// else reduce order and try again
int (*procneigh)[2] = comm->procneigh;
GridComm *cgtmp = NULL;
int iteration = 0;
while (order >= minorder) {
if (iteration && me == 0)
error->warning(FLERR,"Reducing PPPMDipoleSpin order b/c stencil extends "
"beyond nearest neighbor processor");
compute_gf_denom();
set_grid_global(sp2);
set_grid_local();
if (overlap_allowed) break;
cgtmp = new GridComm(lmp,world,1,1,
nxlo_in,nxhi_in,nylo_in,nyhi_in,nzlo_in,nzhi_in,
nxlo_out,nxhi_out,nylo_out,nyhi_out,nzlo_out,nzhi_out,
procneigh[0][0],procneigh[0][1],procneigh[1][0],
procneigh[1][1],procneigh[2][0],procneigh[2][1]);
cgtmp->ghost_notify();
if (!cgtmp->ghost_overlap()) break;
delete cgtmp;
order--;
iteration++;
}
if (order < minorder) error->all(FLERR,"PPPMDipoleSpin order < minimum allowed order");
if (!overlap_allowed && cgtmp->ghost_overlap())
error->all(FLERR,"PPPMDipoleSpin grid stencil extends "
"beyond nearest neighbor processor");
if (cgtmp) delete cgtmp;
// adjust g_ewald
if (!gewaldflag) adjust_gewald();
// calculate the final accuracy
double estimated_accuracy = final_accuracy_dipole(sp2);
// print stats
int ngrid_max,nfft_both_max;
MPI_Allreduce(&ngrid,&ngrid_max,1,MPI_INT,MPI_MAX,world);
MPI_Allreduce(&nfft_both,&nfft_both_max,1,MPI_INT,MPI_MAX,world);
if (me == 0) {
#ifdef FFT_SINGLE
const char fft_prec[] = "single";
#else
const char fft_prec[] = "double";
#endif
if (screen) {
fprintf(screen," G vector (1/distance) = %g\n",g_ewald);
fprintf(screen," grid = %d %d %d\n",nx_pppm,ny_pppm,nz_pppm);
fprintf(screen," stencil order = %d\n",order);
fprintf(screen," estimated absolute RMS force accuracy = %g\n",
estimated_accuracy);
fprintf(screen," estimated relative force accuracy = %g\n",
estimated_accuracy/two_charge_force);
fprintf(screen," using %s precision FFTs\n",fft_prec);
fprintf(screen," 3d grid and FFT values/proc = %d %d\n",
ngrid_max,nfft_both_max);
}
if (logfile) {
fprintf(logfile," G vector (1/distance) = %g\n",g_ewald);
fprintf(logfile," grid = %d %d %d\n",nx_pppm,ny_pppm,nz_pppm);
fprintf(logfile," stencil order = %d\n",order);
fprintf(logfile," estimated absolute RMS force accuracy = %g\n",
estimated_accuracy);
fprintf(logfile," estimated relative force accuracy = %g\n",
estimated_accuracy/two_charge_force);
fprintf(logfile," using %s precision FFTs\n",fft_prec);
fprintf(logfile," 3d grid and FFT values/proc = %d %d\n",
ngrid_max,nfft_both_max);
}
}
// allocate K-space dependent memory
// don't invoke allocate peratom(), will be allocated when needed
allocate();
cg_dipole->ghost_notify();
cg_dipole->setup();
// pre-compute Green's function denominator expansion
// pre-compute 1d charge distribution coefficients
compute_gf_denom();
compute_rho_coeff();
}
/* ----------------------------------------------------------------------
compute the PPPMDipoleSpin long-range force, energy, virial
------------------------------------------------------------------------- */
void PPPMDipoleSpin::compute(int eflag, int vflag)
{
int i,j;
// set energy/virial flags
// invoke allocate_peratom() if needed for first time
if (eflag || vflag) ev_setup(eflag,vflag);
else evflag = evflag_atom = eflag_global = vflag_global =
eflag_atom = vflag_atom = 0;
if (evflag_atom && !peratom_allocate_flag) {
allocate_peratom();
cg_peratom_dipole->ghost_notify();
cg_peratom_dipole->setup();
}
// if atom count has changed, update qsum and qsqsum
if (atom->natoms != natoms_original) {
spsum_spsq();
natoms_original = atom->natoms;
}
// return if there are no spins
if (spsqsum == 0.0) return;
// convert atoms from box to lamda coords
boxlo = domain->boxlo;
// extend size of per-atom arrays if necessary
if (atom->nmax > nmax) {
memory->destroy(part2grid);
nmax = atom->nmax;
memory->create(part2grid,nmax,3,"pppm_spin:part2grid");
}
// find grid points for all my particles
// map my particle charge onto my local 3d on-grid density
particle_map();
make_rho_spin();
// all procs communicate density values from their ghost cells
// to fully sum contribution in their 3d bricks
// remap from 3d decomposition to FFT decomposition
cg_dipole->reverse_comm(this,REVERSE_SP);
brick2fft_dipole();
// compute potential gradient on my FFT grid and
// portion of e_long on this proc's FFT grid
// return gradients (electric fields) in 3d brick decomposition
// also performs per-atom calculations via poisson_peratom()
poisson_ik_dipole();
// all procs communicate E-field values
// to fill ghost cells surrounding their 3d bricks
cg_dipole->forward_comm(this,FORWARD_SP);
// extra per-atom energy/virial communication
if (evflag_atom) {
cg_peratom_dipole->forward_comm(this,FORWARD_SP_PERATOM);
}
// calculate the force on my particles
fieldforce_ik_spin();
// extra per-atom energy/virial communication
if (evflag_atom) fieldforce_peratom_spin();
// sum global energy across procs and add in volume-dependent term
const double spscale = mub2mu0 * scale;
const double g3 = g_ewald*g_ewald*g_ewald;
if (eflag_global) {
double energy_all;
MPI_Allreduce(&energy,&energy_all,1,MPI_DOUBLE,MPI_SUM,world);
energy = energy_all;
energy *= 0.5*volume;
energy -= spsqsum*2.0*g3/3.0/MY_PIS;
energy *= spscale;
}
// sum global virial across procs
if (vflag_global) {
double virial_all[6];
MPI_Allreduce(virial,virial_all,6,MPI_DOUBLE,MPI_SUM,world);
for (i = 0; i < 6; i++) virial[i] = 0.5*spscale*volume*virial_all[i];
}
// per-atom energy/virial
// energy includes self-energy correction
if (evflag_atom) {
double **sp = atom->sp;
double spx,spy,spz;
int nlocal = atom->nlocal;
int ntotal = nlocal;
if (eflag_atom) {
for (i = 0; i < nlocal; i++) {
spx = sp[i][0]*sp[i][3];
spy = sp[i][1]*sp[i][3];
spz = sp[i][2]*sp[i][3];
eatom[i] *= 0.5;
eatom[i] -= (spx*spx + spy*spy + spz*spz)*2.0*g3/3.0/MY_PIS;
eatom[i] *= spscale;
}
}
if (vflag_atom) {
for (i = 0; i < ntotal; i++)
for (j = 0; j < 6; j++) vatom[i][j] *= 0.5*spscale;
}
}
// 2d slab correction
if (slabflag == 1) slabcorr();
}
/* ----------------------------------------------------------------------
create discretized "density" on section of global grid due to my particles
density(x,y,z) = charge "density" at grid points of my 3d brick
(nxlo:nxhi,nylo:nyhi,nzlo:nzhi) is extent of my brick (including ghosts)
in global grid
------------------------------------------------------------------------- */
void PPPMDipoleSpin::make_rho_spin()
{
int l,m,n,nx,ny,nz,mx,my,mz;
FFT_SCALAR dx,dy,dz;
FFT_SCALAR x0,y0,z0;
FFT_SCALAR x1,y1,z1;
FFT_SCALAR x2,y2,z2;
// clear 3d density array
memset(&(densityx_brick_dipole[nzlo_out][nylo_out][nxlo_out]),0,
ngrid*sizeof(FFT_SCALAR));
memset(&(densityy_brick_dipole[nzlo_out][nylo_out][nxlo_out]),0,
ngrid*sizeof(FFT_SCALAR));
memset(&(densityz_brick_dipole[nzlo_out][nylo_out][nxlo_out]),0,
ngrid*sizeof(FFT_SCALAR));
// loop over my charges, add their contribution to nearby grid points
// (nx,ny,nz) = global coords of grid pt to "lower left" of charge
// (dx,dy,dz) = distance to "lower left" grid pt
// (mx,my,mz) = global coords of moving stencil pt
double **sp = atom->sp;
double spx,spy,spz;
double **x = atom->x;
int nlocal = atom->nlocal;
for (int i = 0; i < nlocal; i++) {
nx = part2grid[i][0];
ny = part2grid[i][1];
nz = part2grid[i][2];
dx = nx+shiftone - (x[i][0]-boxlo[0])*delxinv;
dy = ny+shiftone - (x[i][1]-boxlo[1])*delyinv;
dz = nz+shiftone - (x[i][2]-boxlo[2])*delzinv;
compute_rho1d(dx,dy,dz);
spx = sp[i][0]*sp[i][3];
spy = sp[i][1]*sp[i][3];
spz = sp[i][2]*sp[i][3];
z0 = delvolinv * spx;
z1 = delvolinv * spy;
z2 = delvolinv * spz;
for (n = nlower; n <= nupper; n++) {
mz = n+nz;
y0 = z0*rho1d[2][n];
y1 = z1*rho1d[2][n];
y2 = z2*rho1d[2][n];
for (m = nlower; m <= nupper; m++) {
my = m+ny;
x0 = y0*rho1d[1][m];
x1 = y1*rho1d[1][m];
x2 = y2*rho1d[1][m];
for (l = nlower; l <= nupper; l++) {
mx = l+nx;
densityx_brick_dipole[mz][my][mx] += x0*rho1d[0][l];
densityy_brick_dipole[mz][my][mx] += x1*rho1d[0][l];
densityz_brick_dipole[mz][my][mx] += x2*rho1d[0][l];
}
}
}
}
}
/* ----------------------------------------------------------------------
interpolate from grid to get magnetic field & force on my particles for ik
------------------------------------------------------------------------- */
void PPPMDipoleSpin::fieldforce_ik_spin()
{
int i,l,m,n,nx,ny,nz,mx,my,mz;
FFT_SCALAR dx,dy,dz;
FFT_SCALAR x0,y0,z0;
FFT_SCALAR ex,ey,ez;
FFT_SCALAR vxx,vyy,vzz,vxy,vxz,vyz;
// loop over my charges, interpolate electric field from nearby grid points
// (nx,ny,nz) = global coords of grid pt to "lower left" of charge
// (dx,dy,dz) = distance to "lower left" grid pt
// (mx,my,mz) = global coords of moving stencil pt
double **sp = atom->sp;
double spx,spy,spz;
double **x = atom->x;
double **f = atom->f;
double **fm = atom->fm;
int nlocal = atom->nlocal;
for (i = 0; i < nlocal; i++) {
nx = part2grid[i][0];
ny = part2grid[i][1];
nz = part2grid[i][2];
dx = nx+shiftone - (x[i][0]-boxlo[0])*delxinv;
dy = ny+shiftone - (x[i][1]-boxlo[1])*delyinv;
dz = nz+shiftone - (x[i][2]-boxlo[2])*delzinv;
compute_rho1d(dx,dy,dz);
ex = ey = ez = ZEROF;
vxx = vyy = vzz = vxy = vxz = vyz = ZEROF;
for (n = nlower; n <= nupper; n++) {
mz = n+nz;
z0 = rho1d[2][n];
for (m = nlower; m <= nupper; m++) {
my = m+ny;
y0 = z0*rho1d[1][m];
for (l = nlower; l <= nupper; l++) {
mx = l+nx;
x0 = y0*rho1d[0][l];
ex -= x0*ux_brick_dipole[mz][my][mx];
ey -= x0*uy_brick_dipole[mz][my][mx];
ez -= x0*uz_brick_dipole[mz][my][mx];
vxx -= x0*vdxx_brick_dipole[mz][my][mx];
vyy -= x0*vdyy_brick_dipole[mz][my][mx];
vzz -= x0*vdzz_brick_dipole[mz][my][mx];
vxy -= x0*vdxy_brick_dipole[mz][my][mx];
vxz -= x0*vdxz_brick_dipole[mz][my][mx];
vyz -= x0*vdyz_brick_dipole[mz][my][mx];
}
}
}
// convert M-field to mech. and mag. forces
const double spfactor = mub2mu0 * scale;
spx = sp[i][0]*sp[i][3];
spy = sp[i][1]*sp[i][3];
spz = sp[i][2]*sp[i][3];
f[i][0] += spfactor*(vxx*spx + vxy*spy + vxz*spz);
f[i][1] += spfactor*(vxy*spx + vyy*spy + vyz*spz);
f[i][2] += spfactor*(vxz*spx + vyz*spy + vzz*spz);
const double spfactorh = mub2mu0hbinv * scale;
fm[i][0] += spfactorh*ex;
fm[i][1] += spfactorh*ey;
fm[i][2] += spfactorh*ez;
// create a new vector (in atom_spin style ?) to store long-range fm tables
}
}
/* ----------------------------------------------------------------------
interpolate from grid to get per-atom energy/virial
------------------------------------------------------------------------- */
void PPPMDipoleSpin::fieldforce_peratom_spin()
{
int i,l,m,n,nx,ny,nz,mx,my,mz;
FFT_SCALAR dx,dy,dz,x0,y0,z0;
FFT_SCALAR ux,uy,uz;
FFT_SCALAR v0x,v1x,v2x,v3x,v4x,v5x;
FFT_SCALAR v0y,v1y,v2y,v3y,v4y,v5y;
FFT_SCALAR v0z,v1z,v2z,v3z,v4z,v5z;
// loop over my charges, interpolate from nearby grid points
// (nx,ny,nz) = global coords of grid pt to "lower left" of charge
// (dx,dy,dz) = distance to "lower left" grid pt
// (mx,my,mz) = global coords of moving stencil pt
double **sp = atom->sp;
double spx,spy,spz;
double **x = atom->x;
int nlocal = atom->nlocal;
for (i = 0; i < nlocal; i++) {
nx = part2grid[i][0];
ny = part2grid[i][1];
nz = part2grid[i][2];
dx = nx+shiftone - (x[i][0]-boxlo[0])*delxinv;
dy = ny+shiftone - (x[i][1]-boxlo[1])*delyinv;
dz = nz+shiftone - (x[i][2]-boxlo[2])*delzinv;
compute_rho1d(dx,dy,dz);
ux = uy = uz = ZEROF;
v0x = v1x = v2x = v3x = v4x = v5x = ZEROF;
v0y = v1y = v2y = v3y = v4y = v5y = ZEROF;
v0z = v1z = v2z = v3z = v4z = v5z = ZEROF;
for (n = nlower; n <= nupper; n++) {
mz = n+nz;
z0 = rho1d[2][n];
for (m = nlower; m <= nupper; m++) {
my = m+ny;
y0 = z0*rho1d[1][m];
for (l = nlower; l <= nupper; l++) {
mx = l+nx;
x0 = y0*rho1d[0][l];
if (eflag_atom) {
ux += x0*ux_brick_dipole[mz][my][mx];
uy += x0*uy_brick_dipole[mz][my][mx];
uz += x0*uz_brick_dipole[mz][my][mx];
}
if (vflag_atom) {
v0x += x0*v0x_brick_dipole[mz][my][mx];
v1x += x0*v1x_brick_dipole[mz][my][mx];
v2x += x0*v2x_brick_dipole[mz][my][mx];
v3x += x0*v3x_brick_dipole[mz][my][mx];
v4x += x0*v4x_brick_dipole[mz][my][mx];
v5x += x0*v5x_brick_dipole[mz][my][mx];
v0y += x0*v0y_brick_dipole[mz][my][mx];
v1y += x0*v1y_brick_dipole[mz][my][mx];
v2y += x0*v2y_brick_dipole[mz][my][mx];
v3y += x0*v3y_brick_dipole[mz][my][mx];
v4y += x0*v4y_brick_dipole[mz][my][mx];
v5y += x0*v5y_brick_dipole[mz][my][mx];
v0z += x0*v0z_brick_dipole[mz][my][mx];
v1z += x0*v1z_brick_dipole[mz][my][mx];
v2z += x0*v2z_brick_dipole[mz][my][mx];
v3z += x0*v3z_brick_dipole[mz][my][mx];
v4z += x0*v4z_brick_dipole[mz][my][mx];
v5z += x0*v5z_brick_dipole[mz][my][mx];
}
}
}
}
spx = sp[i][0]*sp[i][3];
spy = sp[i][1]*sp[i][3];
spz = sp[i][2]*sp[i][3];
if (eflag_atom) eatom[i] += spx*ux + spy*uy + spz*uz;
if (vflag_atom) {
vatom[i][0] += spx*v0x + spy*v0y + spz*v0z;
vatom[i][1] += spx*v1x + spy*v1y + spz*v1z;
vatom[i][2] += spx*v2x + spy*v2y + spz*v2z;
vatom[i][3] += spx*v3x + spy*v3y + spz*v3z;
vatom[i][4] += spx*v4x + spy*v4y + spz*v4z;
vatom[i][5] += spx*v5x + spy*v5y + spz*v5z;
}
}
}
/* ----------------------------------------------------------------------
Slab-geometry correction term to dampen inter-slab interactions between
periodically repeating slabs. Yields good approximation to 2D Ewald if
adequate empty space is left between repeating slabs (J. Chem. Phys.
111, 3155). Slabs defined here to be parallel to the xy plane. Also
extended to non-neutral systems (J. Chem. Phys. 131, 094107).
------------------------------------------------------------------------- */
void PPPMDipoleSpin::slabcorr()
{
// compute local contribution to global spin moment
double **x = atom->x;
double zprd = domain->zprd;
int nlocal = atom->nlocal;
double spin = 0.0;
double **sp = atom->sp;
double spx,spy,spz;
for (int i = 0; i < nlocal; i++) {
spz = sp[i][2]*sp[i][3];
spin += spz;
}
// sum local contributions to get global spin moment
double spin_all;
MPI_Allreduce(&spin,&spin_all,1,MPI_DOUBLE,MPI_SUM,world);
// compute corrections
const double e_slabcorr = MY_2PI*(spin_all*spin_all/12.0)/volume;
const double spscale = mub2mu0 * scale;
if (eflag_global) energy += spscale * e_slabcorr;
// per-atom energy
if (eflag_atom) {
double efact = spscale * MY_2PI/volume/12.0;
for (int i = 0; i < nlocal; i++) {
spz = sp[i][2]*sp[i][3];
eatom[i] += efact * spz * spin_all;
}
}
// add on mag. force corrections
double ffact = spscale * (-4.0*MY_PI/volume);
double **fm = atom->fm;
for (int i = 0; i < nlocal; i++) {
fm[i][2] += ffact * spin_all;
}
}
/* ----------------------------------------------------------------------
compute spsum,spsqsum,sp2
called initially, when particle count changes, when spins are changed
------------------------------------------------------------------------- */
void PPPMDipoleSpin::spsum_spsq()
{
const int nlocal = atom->nlocal;
spsum = spsqsum = sp2 = 0.0;
if (atom->sp_flag) {
double **sp = atom->sp;
double spx, spy, spz;
double spsum_local(0.0), spsqsum_local(0.0);
// not exactly the good loop: need to add norm of spins
for (int i = 0; i < nlocal; i++) {
spx = sp[i][0]*sp[i][3];
spy = sp[i][1]*sp[i][3];
spz = sp[i][2]*sp[i][3];
spsum_local += spx + spy + spz;
spsqsum_local += spx*spx + spy*spy + spz*spz;
}
MPI_Allreduce(&spsum_local,&spsum,1,MPI_DOUBLE,MPI_SUM,world);
MPI_Allreduce(&spsqsum_local,&spsqsum,1,MPI_DOUBLE,MPI_SUM,world);
sp2 = spsqsum * mub2mu0;
}
if (sp2 == 0 && comm->me == 0)
error->all(FLERR,"Using kspace solver PPPMDipoleSpin on system with no spins");
}

View File

@ -13,28 +13,23 @@
#ifdef KSPACE_CLASS
KSpaceStyle(pppm/spin,PPPMSpin)
KSpaceStyle(pppm/dipole/spin,PPPMDipoleSpin)
#else
#ifndef LMP_PPPM_DIPOLE_H
#define LMP_PPPM_DIPOLE_H
#ifndef LMP_PPPM_DIPOLE_SPIN_H
#define LMP_PPPM_DIPOLE_SPIN_H
#include "pppm.h"
#include "pppm_dipole.h"
namespace LAMMPS_NS {
class PPPMSpin : public PPPM {
class PPPMDipoleSpin : public PPPMDipole {
public:
PPPMSpin(class LAMMPS *, int, char **);
virtual ~PPPMSpin();
PPPMDipoleSpin(class LAMMPS *, int, char **);
virtual ~PPPMDipoleSpin();
void init();
void setup();
void setup_grid();
void compute(int, int);
int timing_1d(int, double &);
int timing_3d(int, double &);
double memory_usage();
protected:
double hbar; // reduced Planck's constant
@ -42,55 +37,15 @@ class PPPMSpin : public PPPM {
double mu_0; // vacuum permeability
double mub2mu0; // prefactor for mech force
double mub2mu0hbinv; // prefactor for mag force
void set_grid_global();
double newton_raphson_f();
void allocate();
void allocate_peratom();
void deallocate();
void deallocate_peratom();
void compute_gf_denom();
void slabcorr();
// grid communication
void pack_forward(int, FFT_SCALAR *, int, int *);
void unpack_forward(int, FFT_SCALAR *, int, int *);
void pack_reverse(int, FFT_SCALAR *, int, int *);
void unpack_reverse(int, FFT_SCALAR *, int, int *);
// spin
FFT_SCALAR ***densityx_brick_spin,***densityy_brick_spin,***densityz_brick_spin;
FFT_SCALAR ***vdxx_brick_spin,***vdyy_brick_spin,***vdzz_brick_spin;
FFT_SCALAR ***vdxy_brick_spin,***vdxz_brick_spin,***vdyz_brick_spin;
FFT_SCALAR ***ux_brick_spin,***uy_brick_spin,***uz_brick_spin;
FFT_SCALAR ***v0x_brick_spin,***v1x_brick_spin,***v2x_brick_spin;
FFT_SCALAR ***v3x_brick_spin,***v4x_brick_spin,***v5x_brick_spin;
FFT_SCALAR ***v0y_brick_spin,***v1y_brick_spin,***v2y_brick_spin;
FFT_SCALAR ***v3y_brick_spin,***v4y_brick_spin,***v5y_brick_spin;
FFT_SCALAR ***v0z_brick_spin,***v1z_brick_spin,***v2z_brick_spin;
FFT_SCALAR ***v3z_brick_spin,***v4z_brick_spin,***v5z_brick_spin;
FFT_SCALAR *work3,*work4;
FFT_SCALAR *densityx_fft_spin,*densityy_fft_spin,*densityz_fft_spin;
class GridComm *cg_spin;
class GridComm *cg_peratom_spin;
int only_spin_flag;
double spsum,spsqsum,sp2;
double find_gewald_spin(double, double, bigint, double, double);
double newton_raphson_f_spin(double, double, bigint, double, double);
double derivf_spin(double, double, bigint, double, double);
double compute_df_kspace_spin();
double compute_qopt_spin();
void compute_gf_spin();
void make_rho_spin();
void brick2fft_spin();
void poisson_ik_spin();
void poisson_peratom_spin();
void fieldforce_ik_spin();
void fieldforce_peratom_spin();
double final_accuracy_spin();
void spsum_spsq();
};
@ -102,9 +57,9 @@ class PPPMSpin : public PPPM {
/* ERROR/WARNING messages:
E: Cannot (yet) use charges with Kspace style PPPMSpin
E: Cannot (yet) use charges with Kspace style PPPMDipoleSpin
Charge-spin interactions are not yet implemented in PPPMSpin so this
Charge-spin interactions are not yet implemented in PPPMDipoleSpin so this
feature is not yet supported.
E: Must redefine kspace_style after changing to triclinic box
@ -123,11 +78,11 @@ E: Cannot (yet) use 'electron' units with spins
This feature is not yet supported.
E: Cannot yet use triclinic cells with PPPMSpin
E: Cannot yet use triclinic cells with PPPMDipoleSpin
This feature is not yet supported.
E: Cannot yet use TIP4P with PPPMSpin
E: Cannot yet use TIP4P with PPPMDipoleSpin
This feature is not yet supported.
@ -207,9 +162,9 @@ outside a processor's sub-domain or even the entire simulation box.
This indicates bad physics, e.g. due to highly overlapping atoms, too
large a timestep, etc.
E: Using kspace solver PPPMSpin on system with no spins
E: Using kspace solver PPPMDipoleSpin on system with no spins
Must have non-zero spins with PPPMSpin.
Must have non-zero spins with PPPMDipoleSpin.
E: Must use kspace_modify gewald for system with no spins

View File

@ -48,7 +48,7 @@ AtomVecSpin::AtomVecSpin(LAMMPS *lmp) : AtomVec(lmp)
comm_x_only = 0;
comm_f_only = 0;
size_forward = 7;
size_reverse = 6;
size_reverse = 9;
size_border = 10;
size_velocity = 3;
size_data_atom = 9;
@ -58,7 +58,6 @@ AtomVecSpin::AtomVecSpin(LAMMPS *lmp) : AtomVec(lmp)
atom->sp_flag = 1;
}
/* ----------------------------------------------------------------------
grow atom arrays
n = 0 grows arrays by a chunk
@ -88,6 +87,7 @@ void AtomVecSpin::grow(int n)
sp = memory->grow(atom->sp,nmax,4,"atom:sp");
fm = memory->grow(atom->fm,nmax*comm->nthreads,3,"atom:fm");
fm_long = memory->grow(atom->fm_long,nmax*comm->nthreads,3,"atom:fm_long");
if (atom->nextra_grow)
for (int iextra = 0; iextra < atom->nextra_grow; iextra++)
@ -103,7 +103,7 @@ void AtomVecSpin::grow_reset()
tag = atom->tag; type = atom->type;
mask = atom->mask; image = atom->image;
x = atom->x; v = atom->v; f = atom->f;
sp = atom->sp; fm = atom->fm;
sp = atom->sp; fm = atom->fm; fm_long = atom->fm_long;
}
@ -342,6 +342,9 @@ int AtomVecSpin::pack_reverse(int n, int first, double *buf)
buf[m++] = fm[i][0];
buf[m++] = fm[i][1];
buf[m++] = fm[i][2];
buf[m++] = fm_long[i][0];
buf[m++] = fm_long[i][1];
buf[m++] = fm_long[i][2];
}
return m;
@ -361,6 +364,9 @@ void AtomVecSpin::unpack_reverse(int n, int *list, double *buf)
fm[j][0] += buf[m++];
fm[j][1] += buf[m++];
fm[j][2] += buf[m++];
fm_long[j][0] += buf[m++];
fm_long[j][1] += buf[m++];
fm_long[j][2] += buf[m++];
}
}
@ -939,6 +945,7 @@ bigint AtomVecSpin::memory_usage()
if (atom->memcheck("sp")) bytes += memory->usage(sp,nmax,4);
if (atom->memcheck("fm")) bytes += memory->usage(fm,nmax*comm->nthreads,3);
if (atom->memcheck("fm_long")) bytes += memory->usage(fm_long,nmax*comm->nthreads,3);
return bytes;
}
@ -947,6 +954,7 @@ void AtomVecSpin::force_clear(int n, size_t nbytes)
{
memset(&atom->f[0][0],0,3*nbytes);
memset(&atom->fm[0][0],0,3*nbytes);
memset(&atom->fm_long[0][0],0,3*nbytes);
}

View File

@ -68,10 +68,12 @@ class AtomVecSpin : public AtomVec {
int *type,*mask;
imageint *image;
double **x,**v,**f; // lattice quantities
double **sp,**fm; // spin quantities
// sp[i][0-2] direction of the spin i
// spin quantities
double **sp; // sp[i][0-2] direction of the spin i
// sp[i][3] atomic magnetic moment of the spin i
double **fm; // fm[i][0-2] direction of magnetic precession
double **fm_long; // storage of long-range spin prec. components
};
}

View File

@ -441,8 +441,6 @@ void PairSpinExchange::allocate()
memory->create(cutsq,n+1,n+1,"pair:cutsq");
}
/* ----------------------------------------------------------------------
proc 0 writes to restart file
------------------------------------------------------------------------- */
@ -527,4 +525,3 @@ void PairSpinExchange::read_restart_settings(FILE *fp)
MPI_Bcast(&offset_flag,1,MPI_INT,0,world);
MPI_Bcast(&mix_flag,1,MPI_INT,0,world);
}

View File

@ -13,19 +13,19 @@
/* ------------------------------------------------------------------------
Contributing authors: Julien Tranchida (SNL)
Stan Moore (SNL)
Please cite the related publication:
Tranchida, J., Plimpton, S. J., Thibaudeau, P., & Thompson, A. P. (2018).
Massively parallel symplectic algorithm for coupled magnetic spin dynamics
and molecular dynamics. arXiv preprint arXiv:1801.10233.
------------------------------------------------------------------------- */
Aidan Thompson (SNL)
Please cite the related publication:
Tranchida, J., Plimpton, S. J., Thibaudeau, P., & Thompson, A. P. (2018).
Massively parallel symplectic algorithm for coupled magnetic spin dynamics
and molecular dynamics. Journal of Computational Physics.
------------------------------------------------------------------------- */
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include "pair_spin_long.h"
#include "atom.h"
#include "comm.h"
@ -80,10 +80,154 @@ PairSpinLong::~PairSpinLong()
{
if (allocated) {
memory->destroy(setflag);
memory->destroy(cutsq);
memory->destroy(cut_spin_long);
}
}
/* ----------------------------------------------------------------------
global settings
------------------------------------------------------------------------- */
void PairSpinLong::settings(int narg, char **arg)
{
if (narg < 1 || narg > 2)
error->all(FLERR,"Incorrect args in pair_style command");
if (strcmp(update->unit_style,"metal") != 0)
error->all(FLERR,"Spin simulations require metal unit style");
cut_spin_long_global = force->numeric(FLERR,arg[0]);
//cut_spin = force->numeric(FLERR,arg[0]);
// reset cutoffs that have been explicitly set
if (allocated) {
int i,j;
for (i = 1; i <= atom->ntypes; i++) {
for (j = i+1; j <= atom->ntypes; j++) {
if (setflag[i][j]) {
cut_spin_long[i][j] = cut_spin_long_global;
}
}
}
}
}
/* ----------------------------------------------------------------------
set coeffs for one or more type pairs
------------------------------------------------------------------------- */
void PairSpinLong::coeff(int narg, char **arg)
{
if (!allocated) allocate();
// check if args correct
if (strcmp(arg[2],"long") != 0)
error->all(FLERR,"Incorrect args in pair_style command");
if (narg != 3)
error->all(FLERR,"Incorrect args in pair_style command");
int ilo,ihi,jlo,jhi;
force->bounds(FLERR,arg[0],atom->ntypes,ilo,ihi);
force->bounds(FLERR,arg[1],atom->ntypes,jlo,jhi);
double spin_long_cut_one = force->numeric(FLERR,arg[3]);
int count = 0;
for (int i = ilo; i <= ihi; i++) {
for (int j = MAX(jlo,i); j <= jhi; j++) {
setflag[i][j] = 1;
cut_spin_long[i][j] = spin_long_cut_one;
count++;
}
}
if (count == 0) error->all(FLERR,"Incorrect args for pair coefficients");
}
/* ----------------------------------------------------------------------
init specific to this pair style
------------------------------------------------------------------------- */
void PairSpinLong::init_style()
{
if (!atom->sp_flag)
error->all(FLERR,"Pair spin requires atom/spin style");
// need a full neighbor list
int irequest = neighbor->request(this,instance_me);
neighbor->requests[irequest]->half = 0;
neighbor->requests[irequest]->full = 1;
// checking if nve/spin is a listed fix
int ifix = 0;
while (ifix < modify->nfix) {
if (strcmp(modify->fix[ifix]->style,"nve/spin") == 0) break;
ifix++;
}
if (ifix == modify->nfix)
error->all(FLERR,"pair/spin style requires nve/spin");
// get the lattice_flag from nve/spin
for (int i = 0; i < modify->nfix; i++) {
if (strcmp(modify->fix[i]->style,"nve/spin") == 0) {
lockfixnvespin = (FixNVESpin *) modify->fix[i];
lattice_flag = lockfixnvespin->lattice_flag;
}
}
// insure use of KSpace long-range solver, set g_ewald
if (force->kspace == NULL)
error->all(FLERR,"Pair style requires a KSpace style");
g_ewald = force->kspace->g_ewald;
}
/* ----------------------------------------------------------------------
init for one type pair i,j and corresponding j,i
------------------------------------------------------------------------- */
double PairSpinLong::init_one(int i, int j)
{
if (setflag[i][j] == 0) error->all(FLERR,"All pair coeffs are not set");
cut_spin_long[j][i] = cut_spin_long[i][j];
return cut_spin_long_global;
}
/* ----------------------------------------------------------------------
extract the larger cutoff if "cut" or "cut_coul"
------------------------------------------------------------------------- */
void *PairSpinLong::extract(const char *str, int &dim)
{
if (strcmp(str,"cut") == 0) {
dim = 0;
return (void *) &cut_spin_long_global;
} else if (strcmp(str,"cut_coul") == 0) {
dim = 0;
return (void *) &cut_spin_long_global;
} else if (strcmp(str,"ewald_order") == 0) {
ewald_order = 0;
ewald_order |= 1<<1;
ewald_order |= 1<<3;
dim = 0;
return (void *) &ewald_order;
} else if (strcmp(str,"ewald_mix") == 0) {
dim = 0;
return (void *) &mix_flag;
}
return NULL;
}
/* ---------------------------------------------------------------------- */
void PairSpinLong::compute(int eflag, int vflag)
@ -95,6 +239,7 @@ void PairSpinLong::compute(int eflag, int vflag)
double evdwl,ecoul;
double xi[3],rij[3];
double spi[4],spj[4],fi[3],fmi[3];
double local_cut2;
double pre1,pre2,pre3;
int *ilist,*jlist,*numneigh,**firstneigh;
@ -156,26 +301,25 @@ void PairSpinLong::compute(int eflag, int vflag)
rij[2] = x[j][2] - xi[2];
rsq = rij[0]*rij[0] + rij[1]*rij[1] + rij[2]*rij[2];
if (rsq < cutsq[itype][jtype]) {
local_cut2 = cut_spin_long[itype][jtype]*cut_spin_long[itype][jtype];
if (rsq < local_cut2) {
r2inv = 1.0/rsq;
rinv = sqrt(r2inv);
if (rsq < cut_spinsq) {
r = sqrt(rsq);
grij = g_ewald * r;
expm2 = exp(-grij*grij);
t = 1.0 / (1.0 + EWALD_P*grij);
erfc = t * (A1+t*(A2+t*(A3+t*(A4+t*A5)))) * expm2;
r = sqrt(rsq);
grij = g_ewald * r;
expm2 = exp(-grij*grij);
t = 1.0 / (1.0 + EWALD_P*grij);
erfc = t * (A1+t*(A2+t*(A3+t*(A4+t*A5)))) * expm2;
bij[0] = erfc * rinv;
bij[1] = (bij[0] + pre1*expm2) * r2inv;
bij[2] = (3.0*bij[1] + pre2*expm2) * r2inv;
bij[3] = (5.0*bij[2] + pre3*expm2) * r2inv;
bij[0] = erfc * rinv;
bij[1] = (bij[0] + pre1*expm2) * r2inv;
bij[2] = (3.0*bij[1] + pre2*expm2) * r2inv;
bij[3] = (5.0*bij[2] + pre3*expm2) * r2inv;
compute_long(i,j,rij,bij,fmi,spi,spj);
compute_long_mech(i,j,rij,bij,fmi,spi,spj);
}
compute_long(i,j,rij,bij,fmi,spi,spj);
compute_long_mech(i,j,rij,bij,fmi,spi,spj);
}
// force accumulation
@ -194,7 +338,7 @@ void PairSpinLong::compute(int eflag, int vflag)
}
if (eflag) {
if (rsq <= cut_spinsq) {
if (rsq <= local_cut2) {
evdwl -= spi[0]*fmi[0] + spi[1]*fmi[1] +
spi[2]*fmi[2];
evdwl *= hbar;
@ -219,6 +363,7 @@ void PairSpinLong::compute_single_pair(int ii, double fmi[3])
double r,rinv,r2inv,rsq;
double grij,expm2,t,erfc;
double bij[4],xi[3],rij[3],spi[4],spj[4];
double local_cut2;
double pre1,pre2,pre3;
int *ilist,*jlist,*numneigh,**firstneigh;
@ -267,25 +412,24 @@ void PairSpinLong::compute_single_pair(int ii, double fmi[3])
rij[2] = x[j][2] - xi[2];
rsq = rij[0]*rij[0] + rij[1]*rij[1] + rij[2]*rij[2];
if (rsq < cutsq[itype][jtype]) {
local_cut2 = cut_spin_long[itype][jtype]*cut_spin_long[itype][jtype];
if (rsq < local_cut2) {
r2inv = 1.0/rsq;
rinv = sqrt(r2inv);
if (rsq < cut_spinsq) {
r = sqrt(rsq);
grij = g_ewald * r;
expm2 = exp(-grij*grij);
t = 1.0 / (1.0 + EWALD_P*grij);
erfc = t * (A1+t*(A2+t*(A3+t*(A4+t*A5)))) * expm2;
r = sqrt(rsq);
grij = g_ewald * r;
expm2 = exp(-grij*grij);
t = 1.0 / (1.0 + EWALD_P*grij);
erfc = t * (A1+t*(A2+t*(A3+t*(A4+t*A5)))) * expm2;
bij[0] = erfc * rinv;
bij[1] = (bij[0] + pre1*expm2) * r2inv;
bij[2] = (3.0*bij[1] + pre2*expm2) * r2inv;
bij[3] = (5.0*bij[2] + pre3*expm2) * r2inv;
bij[0] = erfc * rinv;
bij[1] = (bij[0] + pre1*expm2) * r2inv;
bij[2] = (3.0*bij[1] + pre2*expm2) * r2inv;
bij[3] = (5.0*bij[2] + pre3*expm2) * r2inv;
compute_long(i,j,rij,bij,fmi,spi,spj);
}
compute_long(i,j,rij,bij,fmi,spi,spj);
}
}
@ -361,111 +505,7 @@ void PairSpinLong::allocate()
for (int j = i; j <= n; j++)
setflag[i][j] = 0;
memory->create(cutsq,n+1,n+1,"pair:cutsq");
}
/* ----------------------------------------------------------------------
global settings
------------------------------------------------------------------------- */
void PairSpinLong::settings(int narg, char **arg)
{
if (narg < 1 || narg > 2)
error->all(FLERR,"Incorrect args in pair_style command");
if (strcmp(update->unit_style,"metal") != 0)
error->all(FLERR,"Spin simulations require metal unit style");
cut_spin = force->numeric(FLERR,arg[0]);
}
/* ----------------------------------------------------------------------
set coeffs for one or more type pairs
------------------------------------------------------------------------- */
void PairSpinLong::coeff(int narg, char **arg)
{
if (narg < 4 || narg > 5)
error->all(FLERR,"Incorrect args for pair coefficients");
if (!allocated) allocate();
// check if args correct
if (strcmp(arg[2],"long") != 0)
error->all(FLERR,"Incorrect args in pair_style command");
if (narg != 3)
error->all(FLERR,"Incorrect args in pair_style command");
int ilo,ihi,jlo,jhi;
force->bounds(FLERR,arg[0],atom->ntypes,ilo,ihi);
force->bounds(FLERR,arg[1],atom->ntypes,jlo,jhi);
int count = 0;
for (int i = ilo; i <= ihi; i++) {
for (int j = MAX(jlo,i); j <= jhi; j++) {
setflag[i][j] = 1;
count++;
}
}
if (count == 0) error->all(FLERR,"Incorrect args for pair coefficients");
}
/* ----------------------------------------------------------------------
init for one type pair i,j and corresponding j,i
------------------------------------------------------------------------- */
double PairSpinLong::init_one(int i, int j)
{
if (setflag[i][j] == 0) error->all(FLERR,"All pair coeffs are not set");
double cut = cut_spin;
return cut;
}
/* ----------------------------------------------------------------------
init specific to this pair style
------------------------------------------------------------------------- */
void PairSpinLong::init_style()
{
if (!atom->sp_flag)
error->all(FLERR,"Pair spin requires atom/spin style");
// need a full neighbor list
int irequest = neighbor->request(this,instance_me);
neighbor->requests[irequest]->half = 0;
neighbor->requests[irequest]->full = 1;
// checking if nve/spin is a listed fix
int ifix = 0;
while (ifix < modify->nfix) {
if (strcmp(modify->fix[ifix]->style,"nve/spin") == 0) break;
ifix++;
}
if (ifix == modify->nfix)
error->all(FLERR,"pair/spin style requires nve/spin");
// get the lattice_flag from nve/spin
for (int i = 0; i < modify->nfix; i++) {
if (strcmp(modify->fix[i]->style,"nve/spin") == 0) {
lockfixnvespin = (FixNVESpin *) modify->fix[i];
lattice_flag = lockfixnvespin->lattice_flag;
}
}
// insure use of KSpace long-range solver, set g_ewald
if (force->kspace == NULL)
error->all(FLERR,"Pair style requires a KSpace style");
g_ewald = force->kspace->g_ewald;
cut_spinsq = cut_spin * cut_spin;
memory->create(cut_spin_long,n+1,n+1,"pair:cut_spin_long");
}
/* ----------------------------------------------------------------------
@ -477,10 +517,14 @@ void PairSpinLong::write_restart(FILE *fp)
write_restart_settings(fp);
int i,j;
for (i = 1; i <= atom->ntypes; i++)
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(&cut_spin_long[i][j],sizeof(int),1,fp);
}
}
}
}
/* ----------------------------------------------------------------------
@ -495,11 +539,18 @@ void PairSpinLong::read_restart(FILE *fp)
int i,j;
int me = comm->me;
for (i = 1; i <= atom->ntypes; i++)
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(&cut_spin_long[i][j],sizeof(int),1,fp);
}
MPI_Bcast(&cut_spin_long[i][j],1,MPI_INT,0,world);
}
}
}
}
/* ----------------------------------------------------------------------
@ -508,7 +559,7 @@ void PairSpinLong::read_restart(FILE *fp)
void PairSpinLong::write_restart_settings(FILE *fp)
{
fwrite(&cut_spin,sizeof(double),1,fp);
fwrite(&cut_spin_long_global,sizeof(double),1,fp);
fwrite(&mix_flag,sizeof(int),1,fp);
}
@ -519,32 +570,9 @@ void PairSpinLong::write_restart_settings(FILE *fp)
void PairSpinLong::read_restart_settings(FILE *fp)
{
if (comm->me == 0) {
fread(&cut_spin,sizeof(double),1,fp);
fread(&cut_spin_long_global,sizeof(double),1,fp);
fread(&mix_flag,sizeof(int),1,fp);
}
MPI_Bcast(&cut_spin,1,MPI_DOUBLE,0,world);
MPI_Bcast(&cut_spin_long_global,1,MPI_DOUBLE,0,world);
MPI_Bcast(&mix_flag,1,MPI_INT,0,world);
}
/* ---------------------------------------------------------------------- */
void *PairSpinLong::extract(const char *str, int &dim)
{
if (strcmp(str,"cut") == 0) {
dim = 0;
return (void *) &cut_spin;
} else if (strcmp(str,"cut_coul") == 0) {
dim = 0;
return (void *) &cut_spin;
} else if (strcmp(str,"ewald_order") == 0) {
ewald_order = 0;
ewald_order |= 1<<1;
ewald_order |= 1<<3;
dim = 0;
return (void *) &ewald_order;
} else if (strcmp(str,"ewald_mix") == 0) {
dim = 0;
return (void *) &mix_flag;
}
return NULL;
}

View File

@ -49,6 +49,8 @@ class PairSpinLong : public PairSpin {
void read_restart(FILE *);
void write_restart_settings(FILE *);
void read_restart_settings(FILE *);
double cut_spin_long_global; // global long cutoff distance
protected:
double hbar; // reduced Planck's constant
@ -56,7 +58,8 @@ class PairSpinLong : public PairSpin {
double mu_0; // vacuum permeability
double mub2mu0; // prefactor for mech force
double mub2mu0hbinv; // prefactor for mag force
double cut_spin, cut_spinsq;
double **cut_spin_long; // cutoff distance long
double g_ewald;
int ewald_order;