--- trunk/OOPSE/libmdtools/Thermo.cpp	2003/04/09 04:06:43	483
+++ trunk/OOPSE/libmdtools/Thermo.cpp	2003/07/08 20:56:10	574
@@ -132,10 +132,42 @@ double Thermo::getTemperature(){
   
   temperature = ( 2.0 * this->getKinetic() ) / ((double)entry_plug->ndf * kb );
   return temperature;
+}
+
+double Thermo::getEnthalpy() {
+
+  const double e_convert = 4.184E-4; // convert kcal/mol -> (amu A^2)/fs^2
+  double u, p, v;
+  double press[9];
+
+  u = this->getTotalE();
+
+  this->getPressureTensor(press);
+  p = (press[0] + press[4] + press[8]) / 3.0;
+
+  v = this->getVolume();
+
+  return (u + (p*v)/e_convert);
+}
+
+double Thermo::getVolume() {
+
+  double volume;
+  double Hmat[9];
+
+  entry_plug->getBoxM(Hmat);
+
+  // volume = h1 (dot) h2 (cross) h3
+
+  volume = Hmat[0] * ( (Hmat[4]*Hmat[8]) - (Hmat[7]*Hmat[5]) )
+         + Hmat[1] * ( (Hmat[5]*Hmat[6]) - (Hmat[8]*Hmat[3]) )
+         + Hmat[2] * ( (Hmat[3]*Hmat[7]) - (Hmat[6]*Hmat[4]) );
+
+  return volume;
 }
 
 double Thermo::getPressure() {
-  // returns the pressure in units of atm
+
   // Relies on the calculation of the full molecular pressure tensor
   
   const double p_convert = 1.63882576e8;
@@ -161,13 +193,13 @@ void Thermo::getPressureTensor(double press[9]){
   double vcom[3];
   double p_local[9], p_global[9];
   double theBox[3];
-  double* tau;
+  //double* tau;
   int i, nMols;
   Molecule* molecules;
 
   nMols = entry_plug->n_mol;
   molecules = entry_plug->molecules;
-  tau = entry_plug->tau;
+  //tau = entry_plug->tau;
 
   // use velocities of molecular centers of mass and molecular masses:
   for (i=0; i < 9; i++) {    
@@ -199,12 +231,10 @@ void Thermo::getPressureTensor(double press[9]){
   }
 #endif // is_mpi
 
-  entry_plug->getBox(theBox);
+  volume = entry_plug->boxVol;
 
-  volume = theBox[0] * theBox[1] * theBox[2];
-
   for(i=0; i<9; i++) {
-    press[i] = (p_global[i] - tau[i]*e_convert) / volume;
+    press[i] = (p_global[i] - entry_plug->tau[i]*e_convert) / volume;
   }
 }