lammps/tools/eam_generate/W_Zhou.c

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#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdarg.h>
#include <string.h>
#define EOK 0
#define ERROR -1
#define re 2.74084
#define fe 3.48734
#define rhoe 37.234847
#define alpha 8.900114
#define beta 4.746728
#define A 0.882435
#define B 1.394592
#define kappa 0.139209
#define lambda 0.278417
#define Fn0 -4.946281
#define Fn1 -0.148818
#define Fn2 0.365057
#define Fn3 -4.432406
#define F0 -4.96
#define F1 0.
#define F2 0.661935
#define F3 0.348147
#define eta -0.582714
#define Fe -4.961306
double V (double r) {
return (
( A*exp (-alpha * (r/re-1.) ) ) / (1. + pow (r/re-kappa, 20.))
-
( B*exp (-beta * (r/re-1.) ) ) / (1. + pow (r/re-lambda, 20.))
);
}
double rho (double r) {
return (
(fe * exp (-beta * (r/re-1.))) / (1. + pow (r/re-lambda, 20.))
);
}
double F (double rho_) {
double rhon = .85*rhoe,
rho0 = 1.15*rhoe;
if (rho_ < rhon)
return (
Fn0 * pow (rho_/rhon-1., 0.) +
Fn1 * pow (rho_/rhon-1., 1.) +
Fn2 * pow (rho_/rhon-1., 2.) +
Fn3 * pow (rho_/rhon-1., 3.)
);
else if (rhon <= rho_ && rho_ < rho0)
return (
F0 * pow (rho_/rhoe-1., 0.) +
F1 * pow (rho_/rhoe-1., 1.) +
F2 * pow (rho_/rhoe-1., 2.) +
F3 * pow (rho_/rhoe-1., 3.)
);
else if (rho0 <= rho_)
return (
Fe*(1. - log( pow (rho_/rhoe, eta) ) ) * pow (rho_/rhoe, eta)
);
}
int main (void) {
int Nr = 10001;
double rmax = 2.5*3.157;
double dr = rmax/(double)Nr;
int Nrho = 10001;
double rhomax = rho (0.);
double drho = rhomax/(double)Nrho;
int atomic_number = 1;
double mass = 183.84;
double lattice_constant = 3.157;
char lattice_type[] = "BCC";
int i;
char LAMMPSFilename[] = "W_Zhou.eam";
FILE *LAMMPSFile = fopen (LAMMPSFilename, "w");
if (!LAMMPSFile) exit (ERROR);
// Header for setfl format
fprintf (LAMMPSFile, \
"#-> LAMMPS Potential File in DYNAMO 86 setfl Format <-#\n"\
"# Zhou W Acta mater(2001)49:4005\n"\
"# Implemented by G. Ziegenhain (2007) gerolf@ziegenhain.com\n"\
"%d W\n"\
"%d %20.20f %d %20.20f %20.20f\n"\
"%d %20.20f %20.20f %s\n",
atomic_number,
Nrho, drho, Nr, dr, rmax,
atomic_number, mass, lattice_constant, lattice_type);
// Embedding function
for (i = 0; i < Nrho; i++)
fprintf (LAMMPSFile, "%20.20f\n", F ((double)i*drho));
// Density function
for (i = 0; i < Nr; i++)
fprintf (LAMMPSFile, "%20.20f\n", rho ((double)i*dr));
// Pair potential
for (i = 0; i < Nr; i++)
fprintf (LAMMPSFile, "%20.20f\n", V ((double)i*dr) * (double)i*dr);
fclose (LAMMPSFile);
return (EOK);
}