From owner-chemistry@ccl.net Thu Nov  5 08:29:01 2015
From: "Petra Matunova petra.matunova**seznam.cz" <owner-chemistry,+,server.ccl.net>
To: CCL
Subject: CCL:G: ONIOM calculations in Gaussian
Message-Id: <-51860-151105075408-16537-0v9w3FncpZbswS+Htd4IlA,+,server.ccl.net>
X-Original-From: "Petra  Matunova" <petra.matunova::seznam.cz>
Date: Thu, 5 Nov 2015 07:54:06 -0500


Sent to CCL by: "Petra  Matunova" [petra.matunova]|[seznam.cz]
The surface is hydrogen-terminated and there where should be a continuation to the bulk are hydrogens too (it is a corner of a nanoparticle).


> "zborowsk zborowsk[a]chemia.uj.edu.pl"  wrote:
> 
> Sent to CCL by: zborowsk [zborowsk%chemia.uj.edu.pl]
> 
> I must say I am a bit suprised by presence of hydrogen in your 
> diamond....
> 
> 
> W dniu 2015-11-04 12:06, Petra Matunova petra.matunova]![seznam.cz 
> napisa(a):
> > Sent to CCL by: "Petra  Matunova" [petra.matunova%%seznam.cz]
> > I am performing an ONIOM optimization calculation of a diamond
> > nanoparticle, using b3lyp/6-31g(d):b3lyp/3-21g method. The system
> > contains 206 C atoms and 130 H atoms in the high level and 488 C 
> > atoms
> > 188 H atoms in the low level. When I set the charge and multiplicity
> > as following: 0 1 0 1 0 1, the system do the low level SCF 
> > calculation
> > without problems, but when starts with the  high level calculation on
> > the model system, it ends with error:
> >
> > The combination of multiplicity 1 and  1455 electrons is impossible.
> >
> > It only works when I set  0 1 0 2 0 2. In the high level system there
> > are 1366 electrons plus 89 link electrons from H atoms used as link
> > atoms.
> >
> > I had a problem with the specification of the link atoms on the
> > boundary between the low level and high level system. The low level C
> > atom close to the boundary  has two bonds to another 2 high level C
> > atoms. I haven't known how to deal with that, as far as I know
> > Gaussian allows to specify only one bond to for every low level atom
> > to a high level atom. So I specified for the low level C atom linked
> > to 2 high level C atoms only one link H atom and set the 
> > corresponding
> > scale factor to 1, e.g.:
> >
> >  C      -1     3.953927    3.329465    3.558583 L H 18  1.
> >
> > Like this, I got only a following warning in output, e.g.:
> >
> > WARNING: Link atom host   21 is close to both atoms 18 and  123.
> > Should it be oligovalent?
> >
> > Is there a way how to specify a link of the low level C to both of
> > the high level C to which it is bonded? Or how to solve that, would 
> > it
> > be right to leave the multiplicity to one?
> >
> > Thank you for your help!
> > Best regards,
> > Petra
> >
> >
> >
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> https://www.youtube.com/watch?v=IGyfx3Pmeyk
> Krzysztof K. Zborowski
> Faculty of Chemistry
> Jagiellonian University
> 3 Ingardena Street
> 30-060 Krakow
> Poland
> phone: +48(12)663-2067
> email: zborowsk]~[chemia.uj.edu.pl
> gg 3817259
> skype kzys70
> www.chemia.uj.edu.pl/~zborowsk
> 
>