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Added NPzzHug Hugoniostat 

git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@6750 f3b2605a-c512-4ea7-a41b-209d697bcdaa
This commit is contained in:
athomps 2011-08-21 20:43:42 +00:00
parent 94fc87cf12
commit 3f21a1aad6
2 changed files with 32 additions and 20 deletions
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47
src/fix_nh.cpp
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@ -641,10 +641,13 @@ void FixNH::setup(int vflag)
tdof = temperature->dof;
// t_target is used by compute_scalar(), even for NPH
// t_target is needed by NPH and NPT in compute_scalar()
// If no thermostat,
// t_target must be defined by other means.
if (tstat_flag) t_target = t_start;
else if (pstat_flag) {
if (tstat_flag) {
compute_temp_target();
} else if (pstat_flag) {
// t0 = initial value for piston mass and energy conservation
// cannot be done in init() b/c temperature cannot be called there
@ -680,7 +683,7 @@ void FixNH::setup(int vflag)
eta_mass[ich] = boltz * t_target / (t_freq*t_freq);
for (int ich = 1; ich < mtchain; ich++) {
eta_dotdot[ich] = (eta_mass[ich-1]*eta_dot[ich-1]*eta_dot[ich-1] -
boltz*t_target) / eta_mass[ich];
boltz * t_target) / eta_mass[ich];
}
}
@ -706,7 +709,7 @@ void FixNH::setup(int vflag)
for (int ich = 1; ich < mpchain; ich++)
etap_dotdot[ich] =
(etap_mass[ich-1]*etap_dot[ich-1]*etap_dot[ich-1] -
boltz*t_target) / etap_mass[ich];
boltz * t_target) / etap_mass[ich];
}
}
@ -725,9 +728,7 @@ void FixNH::initial_integrate(int vflag)
// update eta_dot
if (tstat_flag) {
double delta = update->ntimestep - update->beginstep;
delta /= update->endstep - update->beginstep;
t_target = t_start + delta * (t_stop-t_start);
compute_temp_target();
eta_mass[0] = tdof * boltz * t_target / (t_freq*t_freq);
for (int ich = 1; ich < mtchain; ich++)
eta_mass[ich] = boltz * t_target / (t_freq*t_freq);
@ -826,9 +827,7 @@ void FixNH::initial_integrate_respa(int vflag, int ilevel, int iloop)
// update eta_dot
if (tstat_flag) {
double delta = update->ntimestep - update->beginstep;
delta /= update->endstep - update->beginstep;
t_target = t_start + delta * (t_stop-t_start);
compute_temp_target();
eta_mass[0] = tdof * boltz * t_target / (t_freq*t_freq);
for (int ich = 1; ich < mtchain; ich++)
eta_mass[ich] = boltz * t_target / (t_freq*t_freq);
@ -1305,7 +1304,6 @@ double FixNH::compute_scalar()
double volume;
double energy;
double kt = boltz * t_target;
double lkt = tdof * kt;
double lkt_press = kt;
int ich;
if (dimension == 3) volume = domain->xprd * domain->yprd * domain->zprd;
@ -1323,7 +1321,7 @@ double FixNH::compute_scalar()
// Q_k = k*T/t_freq^2, k > 1
if (tstat_flag) {
energy += lkt * eta[0] + 0.5*eta_mass[0]*eta_dot[0]*eta_dot[0];
energy += ke_target * eta[0] + 0.5*eta_mass[0]*eta_dot[0]*eta_dot[0];
for (ich = 1; ich < mtchain; ich++)
energy += kt * eta[ich] + 0.5*eta_mass[ich]*eta_dot[ich]*eta_dot[ich];
}
@ -1430,7 +1428,6 @@ double FixNH::compute_vector(int n)
double volume;
double kt = boltz * t_target;
double lkt = tdof * kt;
double lkt_press = kt;
int ich;
if (dimension == 3) volume = domain->xprd * domain->yprd * domain->zprd;
@ -1441,7 +1438,7 @@ double FixNH::compute_vector(int n)
if (n < ilen) {
ich = n;
if (ich == 0)
return lkt * eta[0];
return ke_target * eta[0];
else
return kt * eta[ich];
}
@ -1581,9 +1578,8 @@ void FixNH::nhc_temp_integrate()
int ich;
double expfac;
double lkt = tdof * boltz * t_target;
double kecurrent = tdof * boltz * t_current;
eta_dotdot[0] = (kecurrent - lkt)/eta_mass[0];
eta_dotdot[0] = (kecurrent - ke_target)/eta_mass[0];
double ncfac = 1.0/nc_tchain;
for (int iloop = 0; iloop < nc_tchain; iloop++) {
@ -1610,7 +1606,7 @@ void FixNH::nhc_temp_integrate()
t_current *= factor_eta*factor_eta;
kecurrent = tdof * boltz * t_current;
eta_dotdot[0] = (kecurrent - lkt)/eta_mass[0];
eta_dotdot[0] = (kecurrent - ke_target)/eta_mass[0];
for (ich = 0; ich < mtchain; ich++)
eta[ich] += ncfac*dthalf*eta_dot[ich];
@ -1975,6 +1971,21 @@ void FixNH::compute_deviatoric()
h[4]*( sigma[3]*h[1]+sigma[2]*h[3]);
}
/* ----------------------------------------------------------------------
compute target temperature and kinetic energy
-----------------------------------------------------------------------*/
void FixNH::compute_temp_target()
{
double delta = update->ntimestep - update->beginstep;
if (update->endstep > update->beginstep)
delta /= update->endstep - update->beginstep;
else delta = 0.0;
t_target = t_start + delta * (t_stop-t_start);
ke_target = tdof * boltz * t_target;
}
/* ----------------------------------------------------------------------
compute hydrostatic target pressure
-----------------------------------------------------------------------*/

5
src/fix_nh.h
View File

@ -24,7 +24,7 @@ class FixNH : public Fix {
virtual ~FixNH();
int setmask();
virtual void init();
void setup(int);
virtual void setup(int);
virtual void initial_integrate(int);
virtual void final_integrate();
void initial_integrate_respa(int, int, int);
@ -45,7 +45,7 @@ class FixNH : public Fix {
double vol0,t0;
double t_start,t_stop;
double t_current,t_target;
double t_current,t_target,ke_target;
double t_freq;
int tstat_flag; // 1 if control T
@ -113,6 +113,7 @@ class FixNH : public Fix {
virtual void nve_v();
virtual void nh_v_press();
virtual void nh_v_temp();
virtual void compute_temp_target();
void compute_sigma();
void compute_deviatoric();