[gmx-users] potential energy in force.c

[Nguyen Hoang Phuong]

Dear All,

at the end of the code /src/mdlib/force.c there is a variable
epot[F_EPOT] which is calculated as

 for(i=0; (i<F_EPOT); i++)
    if (i != F_DISRES)
      epot[F_EPOT]+=epot[i];


Is epot[F_EPOT] the total potential energy of the system?

I print this value by changing the above lines to

for(i=0; (i<F_EPOT); i++){
    if (i != F_DISRES)
      epot[F_EPOT]+=epot[i];
  }

printf("%lf\n",epot[F_EPOT]);

I compare this value with the total potential energy of the system
obtained by the program g_energy, however they are quite different with each other. Am I
missing something?

Thanks a lot in advance for any explaination,

Phuong