static real phi_sr(FILE *log,int nj,rvec x[],real charge[],real rc,real r1,rvec box,
real phi[],t_block *excl,rvec f_sr[],bool bOld)
{
int i,j,k,m,ni,i1,i2;
real pp,r2,R,R_1,R_2,rc2;
real qi,qj,vsr,eps,fscal;
rvec dx;
vsr = 0.0;
eps = ONE_4PI_EPS0;
rc2 = rc*rc;
ni=0;
for(i=0; (i<nj-1); i++) {
qi=charge[i];
for(j=i+1; (j<nj); j++) {
i1=excl->index[i];
i2=excl->index[i+1];
for(k=i1; (k<i2); k++)
if (excl->a[k] == j)
break;
if (k == i2) {
r2=calc_dx2dx(x[i],x[j],box,dx);
if (r2 < rc2) {
qj = charge[j];
R_1 = invsqrt(r2);
R_2 = R_1*R_1;
R = invsqrt(R_2);
if (bOld) {
fscal = old_f(R,rc,r1)*R_2;
pp = old_phi(R,rc,r1);
}
else {
fscal = new_f(R,rc)*R_2;
pp = new_phi(R,rc);
}
phi[i] += eps*qj*pp;
phi[j] += eps*qi*pp;
vsr += eps*qj*qi*pp;
for(m=0; (m<DIM); m++) {
f_sr[i][m] += dx[m]*fscal;
f_sr[j][m] -= dx[m]*fscal;
}
ni++;
}
}
}
}
fprintf(log,"There were %d short range interactions, vsr=%g\n",ni,vsr);
return vsr;
}
real calc_dx2(rvec xi,rvec xj,rvec box)
{
rvec dx;
return calc_dx2dx(xi,xj,box,dx);
}
