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git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@818 f3b2605a-c512-4ea7-a41b-209d697bcdaa

This commit is contained in:
sjplimp 2007-08-22 13:48:11 +00:00
parent 407209dcf3
commit 6f1c2637b9
2 changed files with 43 additions and 0 deletions
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42
src/CLASS2/angle_class2.cpp
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@ -423,3 +423,45 @@ void AngleClass2::read_restart(FILE *fp)
for (int i = 1; i <= atom->nangletypes; i++) setflag[i] = 1;
}
/* ---------------------------------------------------------------------- */
double AngleClass2::single(int type, int i1, int i2, int i3)
{
double **x = atom->x;
double delx1 = x[i1][0] - x[i2][0];
double dely1 = x[i1][1] - x[i2][1];
double delz1 = x[i1][2] - x[i2][2];
domain->minimum_image(delx1,dely1,delz1);
double r1 = sqrt(delx1*delx1 + dely1*dely1 + delz1*delz1);
double delx2 = x[i3][0] - x[i2][0];
double dely2 = x[i3][1] - x[i2][1];
double delz2 = x[i3][2] - x[i2][2];
domain->minimum_image(delx2,dely2,delz2);
double r2 = sqrt(delx2*delx2 + dely2*dely2 + delz2*delz2);
double c = delx1*delx2 + dely1*dely2 + delz1*delz2;
c /= r1*r2;
if (c > 1.0) c = 1.0;
if (c < -1.0) c = -1.0;
double s = sqrt(1.0 - c*c);
if (s < SMALL) s = SMALL;
s = 1.0/s;
double dtheta = acos(c) - theta0[type];
double dtheta2 = dtheta*dtheta;
double dtheta3 = dtheta2*dtheta;
double dtheta4 = dtheta3*dtheta;
double energy = k2[type]*dtheta2 + k3[type]*dtheta3 + k4[type]*dtheta4;
double dr1 = r1 - bb_r1[type];
double dr2 = r2 - bb_r2[type];
energy += bb_k[type]*dr1*dr2;
energy += ba_k1[type]*dr1*dtheta + ba_k2[type]*dr2*dtheta;
return energy;
}

1
src/CLASS2/angle_class2.h
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@ -28,6 +28,7 @@ class AngleClass2 : public Angle {
double equilibrium_angle(int);
void write_restart(FILE *);
void read_restart(FILE *);
double single(int, int, int, int);
private:
double *theta0,*k2,*k3,*k4;