[gmx-users] Re: QM/MM simulations

Justin Lemkul jalemkul at vt.edu
Wed Jun 26 13:49:00 CEST 2013

On 6/26/13 7:02 AM, DavidPO wrote:
> Thank you!
> It's work. But another problem has appeared.
> Apparently this is some error associated with ORCA connecting:
> Back Off! I just backed up md.log to ./#md.log.5#
> Reading file topol.tpr, VERSION 4.6 (single precision)
> Using 1 MPI thread
> QM/MM calculation requested.
> Layer 0
> nr of QM atoms 30
> QMlevel: CASSCF/STO-3G
> /home/timofeev/ORCA/orca/home/timofeev/ORCA/orca...
> orca initialised...
> Back Off! I just backed up traj.trr to ./#traj.trr.4#
> Back Off! I just backed up traj.xtc to ./#traj.xtc.4#
> Back Off! I just backed up ener.edr to ./#ener.edr.4#
> starting mdrun 'GRowing Old MAkes el Chrono Sweat in water'
> 2000 steps,      1.0 ps.
> No information on the calculation given in <topol.tpr.ORCAINFO>
> Source code file: /home/timofeev/GROMACS/gromacs-4.6/src/mdlib/qm_orca.c,
> line: 161
> Routine should not have been called:
> qm_orca.c
> I couldn't found rather information about it.
> Please, comment it.

Apparently, some additional input file ($BASENAME.ORCAINFO) is required, and is 
supposed to contain ORCA-specific instructions for the calculation.  I don't do 
QM/MM, so I haven't spent much time looking online for tutorials and such. 
Perhaps the information at http://wwwuser.gwdg.de/~ggroenh/qmmm.html is useful. 
  Note that $BASENAME should be the .tpr prefix and should not include the .tpr 
file extension.



Justin A. Lemkul, Ph.D.
Research Scientist
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080


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