[gmx-users] problems with QM/MM in gromacs-CPMD

[Gireesh M Krishnan]

Dear gromacs users,
I wanted to run a QM/MM calculation in gromacs. we
have installed the Gromacs-CPMD interface in our
system. In order to make a test run, i tried to run
one of the examples provided- ie. energy minimization
of H2O dimer. I have chosen the top, gro, mdp files
given and tried to run. also I have the bond type of
QM atoms to 5 in the topology file. though program
seemed finished successfully, but in the 'qm_cpmd.out'
file the QM forces have been written as all zero!  it
printed as follows

 Printing QM forces on QM atoms in A.U.
3 0.000000 0.000000 0.000000
4 0.000000 0.000000 0.000000
5 0.000000 0.000000 0.000000
QM-Energies: internal = 0.000000, external = 0.000000
                                                      
                                                      
                                               
 Printing QM/MM forces on inner layer atoms in AU
0 0.000000 0.000000 0.000000
1 0.000000 0.000000 0.000000
2 0.000000 0.000000 0.000000
                                                      
                                                      
                                               
 QM & QM/MM forces after qm-call in KJ/mol/nm
0 0.000000 0.000000 0.000000
1 0.000000 0.000000 0.000000
2 0.000000 0.000000 0.000000
3 0.000000 0.000000 0.000000
4 0.000000 0.000000 0.000000
5 0.000000 0.000000 0.000000

from this output can anyone speculate what might have
gone wrong? any advice or suggestion will be very much
helpful..
thanks in advance

Gireesh


		
__________________________________________________________
Yahoo! India Answers: Share what you know. Learn something new
http://in.answers.yahoo.com/