git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@4770 f3b2605a-c512-4ea7-a41b-209d697bcdaa

This commit is contained in:
sjplimp 2010-09-10 17:28:15 +00:00
parent d00a76fdea
commit 9a0acc9585
3 changed files with 21 additions and 4 deletions

View File

@ -38,6 +38,9 @@ FixTempBerendsen::FixTempBerendsen(LAMMPS *lmp, int narg, char **arg) :
// Berendsen thermostat should be applied every step
nevery = 1;
scalar_flag = 1;
global_freq = nevery;
extscalar = 1;
t_start = atof(arg[3]);
t_stop = atof(arg[4]);
@ -62,6 +65,8 @@ FixTempBerendsen::FixTempBerendsen(LAMMPS *lmp, int narg, char **arg) :
modify->add_compute(3,newarg);
delete [] newarg;
tflag = 1;
energy = 0;
}
/* ---------------------------------------------------------------------- */
@ -80,6 +85,7 @@ int FixTempBerendsen::setmask()
{
int mask = 0;
mask |= END_OF_STEP;
mask |= THERMO_ENERGY;
return mask;
}
@ -106,7 +112,7 @@ void FixTempBerendsen::end_of_step()
double delta = update->ntimestep - update->beginstep;
delta /= update->endstep - update->beginstep;
t_target = t_start + delta * (t_stop-t_start);
double t_target = t_start + delta * (t_stop-t_start);
// rescale velocities by lamda
// for BIAS:
@ -114,6 +120,8 @@ void FixTempBerendsen::end_of_step()
// OK to not test returned v = 0, since lamda is multiplied by v
double lamda = sqrt(1.0 + update->dt/t_period*(t_target/t_current - 1.0));
double efactor = 0.5 * force->boltz * temperature->dof;
energy += t_current * (1.0-lamda*lamda) * efactor;
double **v = atom->v;
int *mask = atom->mask;
@ -174,3 +182,10 @@ void FixTempBerendsen::reset_target(double t_new)
{
t_start = t_stop = t_new;
}
/* ---------------------------------------------------------------------- */
double FixTempBerendsen::compute_scalar()
{
return energy;
}

View File

@ -33,10 +33,12 @@ class FixTempBerendsen : public Fix {
void end_of_step();
int modify_param(int, char **);
void reset_target(double);
double compute_scalar();
private:
int which;
double t_start,t_stop,t_target,t_period;
double t_start,t_stop,t_period;
double energy;
char *id_temp;
class Compute *temperature;

View File

@ -127,8 +127,9 @@ void FixTempRescale::end_of_step()
int *mask = atom->mask;
int nlocal = atom->nlocal;
energy += (t_current-t_target) * efactor;
if (which == NOBIAS) {
energy += (t_current-t_target) * efactor;
for (int i = 0; i < nlocal; i++) {
if (mask[i] & groupbit) {
v[i][0] *= factor;
@ -137,7 +138,6 @@ void FixTempRescale::end_of_step()
}
}
} else {
energy += (t_current-t_target) * efactor;
for (int i = 0; i < nlocal; i++) {
if (mask[i] & groupbit) {
temperature->remove_bias(i,v[i]);