Reading command-line arguments and input files...
Loading and checking parameter files for compatibility...
sander found! Using /usr/local/amber12/bin/sander
mmpbsa_py_energy found! Using /usr/local/amber12/bin/mmpbsa_py_energy
cpptraj found! Using /usr/local/amber12/bin/cpptraj
Preparing trajectories for simulation...
50 frames were processed by cpptraj for use in calculation.

Beginning PB calculations with /usr/local/amber12/bin/sander
  calculating complex contribution...

  Error opening unit   30: File "_MMPBSA_dummycomplex.inpcrd" is missing or unreadable                
CalcError: /usr/local/amber12/bin/sander failed with prmtop ras-raf.prmtop!
Exiting. All files have been retained.