[gmx-users] ask help for Potential energy curve calculation

[Yunan Yan]

Dear all,

Now I need use GROMACS/CPMD to calculate the potential energy
curve for a molecular solved in liquid. Please see the related
content of the CPMD_inp.tmpl and the output for the details.

$ cat em.mdp
title               =  AU
cpp                 =  /usr/bin/cpp
constraints         =  all-bonds
constraint_algorithm= shake
integrator          =  steep
nsteps              =  50
...........................
............................
QMMM                =  yes
QMmethod            =  CPMD
QMMMscheme          =  normal
QMMM-grps           =  QM
QMbasis             =  STO-3G
planewavecutoff     =  25
qmmmcoul_cutoff     =  25
MMlayer_radii       =  10 10
MMlayer_updfqs      =  1  1
;  box for cpmd run in a.u.
qmbox_cpmd          =  40.0000   30.0000   30.0000

$ head -7 CPMD_inp.tmpl
&CPMD
    INTERFACE GMX PCGFIRST
    PCG MINIMIZE
    MOLECULE CENTER OFF
    OPTIMIZE WAVEFUNCTION
&END

$ cat output.em

       THE FOLLOWING OPTIONS ARE MUTUALLY  EXCLUSIVE
                                  MOLECULAR DYNAMICS
                               GEOMETRY OPTIMIZATION
                           WAVEFUNCTION OPTIMIZATION
                                  KOHN-SHAM ENERGIES
                                VIBRATIONAL ANALYSIS
                                          PROPERTIES
                                    ORBITAL HARDNESS
                                  ELECTRONIC SPECTRA
                                        DEBUG FORCES
                                     LINEAR RESPONSE
                                 CLASSICAL INTERFACE


 PROGRAM STOPS IN SUBROUTINE CONTROL| RUNOPTIONS

Would anyone tell me how I can calculte potential energy
curve with Gromacs/CPMD if the interface GMX and the
OPTIMIZE option cannot be used at the same time?

Thank you so much.

Best regards,
Yun-an