用c++写一个简单的分子动力学程序
时间: 2023-03-29 15:04:28 浏览: 115
好的,我可以回答这个问题。分子动力学程序是一种用于模拟分子运动的计算机程序。以下是一个简单的分子动力学程序的代码示例:
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define N 100
#define L 10.
#define dt .01
#define T 100
double x[N], y[N], z[N];
double vx[N], vy[N], vz[N];
double fx[N], fy[N], fz[N];
double rand_normal(double mean, double stddev) {
double u1 = rand() / (RAND_MAX + 1.);
double u2 = rand() / (RAND_MAX + 1.);
double z = sqrt(-2. * log(u1)) * cos(2. * M_PI * u2);
return mean + stddev * z;
}
void init() {
int i;
for (i = ; i < N; i++) {
x[i] = rand_normal(L / 2., L / 10.);
y[i] = rand_normal(L / 2., L / 10.);
z[i] = rand_normal(L / 2., L / 10.);
vx[i] = rand_normal(., 1.);
vy[i] = rand_normal(., 1.);
vz[i] = rand_normal(., 1.);
}
}
void force() {
int i, j;
double r, r2, r6, f;
for (i = ; i < N; i++) {
fx[i] = fy[i] = fz[i] = .;
for (j = ; j < N; j++) {
if (i == j) continue;
r2 = (x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]) + (z[i] - z[j]) * (z[i] - z[j]);
if (r2 > L * L / 4.) continue;
r = sqrt(r2);
r6 = r2 * r2 * r2;
f = 24. * (2. / r6 - 1. / r6 / r6) / r2;
fx[i] += f * (x[i] - x[j]);
fy[i] += f * (y[i] - y[j]);
fz[i] += f * (z[i] - z[j]);
}
}
}
void integrate() {
int i;
for (i = ; i < N; i++) {
vx[i] += fx[i] * dt;
vy[i] += fy[i] * dt;
vz[i] += fz[i] * dt;
x[i] += vx[i] * dt;
y[i] += vy[i] * dt;
z[i] += vz[i] * dt;
if (x[i] < .) x[i] += L;
if (x[i] > L) x[i] -= L;
if (y[i] < .) y[i] += L;
if (y[i] > L) y[i] -= L;
if (z[i] < .) z[i] += L;
if (z[i] > L) z[i] -= L;
}
}
int main() {
int t, i;
init();
for (t = ; t < T; t++) {
force();
integrate();
if (t % 10 == ) {
printf("%d\n", N);
printf("t = %d\n", t);
for (i = ; i < N; i++) {
printf("Ar %lf %lf %lf\n", x[i], y[i], z[i]);
}
}
}
return ;
}