Re: [AMBER] qm2_extern_gau_module

From: David Poole <thepoole.ucdavis.edu>
Date: Sat, 6 Jan 2018 23:48:40 +0100

Hello Thakur,

I really hate double posting, but sometimes I get to learn google keyboard
shortcuts. That said..
You shouldn't need to specify your version of Gaussian, the module will
check which version is in your path for you. I believe everyone else is
saying this.
If you are having problems with the method of basis, I'd really suggest
using your own template file (this is well documented). It allows a greater
flexibility in your calculations, e.q. using quadratic convergence for the
self-consistent field.


On a related suggestion, I had encountered some errors when running Amber
14 with QMMD using the qm2_extern module, this has to do with the formchk
utility behaving differently than expected. To get it to work, I modified
the conditional at line 157 of the Fortran code to ignore the return value.
However, in the end I found g09 rev D was more efficient to use with Amber
and would suggest you the same.

Here is a complete input file for doing QMMD that I use, carefully review
the gau and qmmm portions and look up what each parameter does and how you
need to modify it for your use case.
&cntrl
 imin=0, ntb=0, ig=-1, irest=0,
 cut=9999.0,
 tempi=0.0, temp0=350,
 ntt = 3, gamma_ln = 5.0,
 ifqnt=1,
 nstlim=2500, dt=0.001,
 ntpr=1, ntwx=1, ntwf=1, ifqnt=1
&end
 &qmmm
  qmmask='*',
  spin=1,
  qmcharge=-2,
  qm_theory='EXTERN',
  qmcut=99999
 &end
 &gau
  num_threads=16,
  mem=25GB,
  use_template=1
 &end

Note that I am using a template, this is just the route section of a
gaussian input file, e.g.
# ub3lyp/def2SVP integral=grid=ultraf1ine scf=qc


That said, good luck and tot zeins.

-David

On 6 January 2018 at 23:42, David Poole <thepoole.ucdavis.edu> wrote:

> Hello Thakur,
>
> You shouldn't need to specify your version of Gaussian, the module will
> check which version is in your path for you. I believe everyone else is
> saying this.
>
> If you are having problems with the method of basis, I'd really suggest
> using your own template file (this is well documented). It allows a greater
> flexibility in your calculations, e.q. using quadratic convergence for the
> self-consistent field.
>
> Also, I have encountered some errors when running Amber 14 with QMMD using
> the qm2_extern module, this has to do with the formchk utility behaving
> differently than expected. For better or worse I'd modified the module to
> simply ignore the return value of formchk.
>
> Here is a complete input file for doing QMMD
> &cntrl
> imin=0, ntb=0, ig=-1, irest=0,
> cut=9999.0,
> tempi=0.0, temp0=350,
> ntt = 3, gamma_ln = 5.0,
> ifqnt=1,
> nstlim=2500, dt=0.001,
> ntpr=1, ntwx=1, ntwf=1, ifqnt=1
> &end
> &qmmm
> qmmask='10',
> qmcharge=-2,
>
> qm_theory='EXTERN',
> qmcut=99999
> &end
> &gau
> num_threads=16,
> mem=25GB,
> use_template=1
> &end
>
> Note to change the
>
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Received on Sat Jan 06 2018 - 15:00:02 PST
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