Did you heat/equilibrate your system using just MM before starting the
QM/MM run ?
Adrian
On 10/14/11 3:58 PM, Yao Yao wrote:
> Hi,
>
> I am following QMMMMD tutorial online to do a regular protein test job. However,
> I found my system Density and Volume increase linearly after several ps simulation.
>
> And the temp is stable at around 350 K on average, rather than the expected 300 K.
>
> I guess my system is blowing up. Here I post my production run input file,
>
> ===================
> 300K constant temp QMMMMD
> &cntrl
> imin=0, ntb=2,
> cut=8.0, ntc=2, ntf=2,
> tempi=300.0, temp0=300.0,
> ntt=3, gamma_ln=1,
> ntp=1, taup=2.0,pres0=1,
> nstlim=5000, dt=0.002,
> ntpr=10, ntwx=10,ifqnt=1
> /
> &qmmm
> qmmask=':1',
> qmcharge=0,
> qmtheory=1,
> qmshake=1,
> qm_ewald=1, qm_pme=1
> /
>
>
> =====================
> Is this because my simulation is not long enough, or maybe I should do energy minimization more properly?
>
> Thanks,
>
> Yao
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--
Dr. Adrian E. Roitberg
Professor
Quantum Theory Project, Department of Chemistry
University of Florida
roitberg.ufl.edu
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Received on Fri Oct 14 2011 - 13:30:03 PDT
