Hi Here is my pdb file. #!/bin/bash #PBS -l nodes=2 cat $PBS_NODEFILE echo Working directory is $PBS_O_WORKDIR cd $PBS_O_WORKDIR mpirun -np 2 g_energy_mpi -f minim_ener.edr -o minim_ener.xvg 11 0 Then, it showed Fatal error: No energy terms selected How to fix the problem Thank you Lin