CCL:G: AIM

 Sent to CCL by: =?iso-8859-1?Q?V=EDctor_Lua=F1a?= Cabal
 [victor===fluor.quimica.uniovi.es]
 On Sun, Nov 27, 2016 at 08:55:09AM +0800, 郭建东
 guojiandong13() mails.ucas.ac.cn wrote:
 >
 > Dear Prof. Víctor Luaña
 >       I am a beginner of computational chemistry. I have little
 > knowledge of AIM. I did not try  whether the AIM can be performed on
 > Gaussuan 09.
 ¿Are you asking why not using the AIM facility internal to g09?
 Dont! The AIM algorithms within g09 fails in too many occasions and they
 are not useful, in general. In fact, failures in the g09 aim algorithm
 have always been a source of concern for the people doing QTAIM work.
 Use an independent code. The original AIMPAC from the Bader's
 group is still available (1), but newer codes have improved
 characteristics. Directly from Bader's students you have: aim2000
 and aimall.
 (1) <http://www.chemistry.mcmaster.ca/aimpac/imagemap/imagemap.htm>;
 My group, that went to study with Bader's group after we had created
 independently codes to to do AIM studies on solid state problems,
 published critic as an open source code. The original critic was intended
 to analyse the electron density and its laplacian in solids. It was
 heavily improved in critic2, also open source, that works both on
 crystals and molecules and implements a special computational langage
 to create new tasks not hard coded in the critic2 source.
 There are also excellent QTAIM codes by PLA. Popelier, from Manchester
 University but I'm not currently sure how they can be obtained. You must
 explore that if you want. Popelier has written that QCT (quantum chemistry
 topology of topography) is a better name that QTAIM. The reason is that
 QTAIM analysis can be extended to other scalar properties within the
 electron density basins.
 There is also a chinese code, multiwfn, but the algorithms implemented
 there prefer que quantity of doing many things to que quality of doing
 them well.
 So, my advise is: do not use the g09 internal aim task! Use aimall
 or critic2 to analyse the g09 WFX file that g09 produces. NOtice that
 WFX improves on the WFN format that g03 (surely even previous gaussian
 versions) started to produce to give AIMPAC programs the wavefunction
 to explore. Most Bader's articles were done that way.
 If you need to study what is the AIM analysis you should read Bader's
 book:  Bader, Richard (1994). Atoms in Molecules: A Quantum Theory. USA:
 Oxford University Press. ISBN 978-0-19-855865-1.
 I started to write this message without realizing that you were using the
 CCL list. Maybe this is a too personal opinion for a Universal audience,
 but I do not regret having strong opinions and showing them clearly.
 Enjoy,
       Dr. Víctor Luaña
 --
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 ==(((==)))==================================+===========================
 ! Dr.Víctor Luaña, in silico chemist & prof. !
 ! Departamento de Química Física y Analítica !
 ! Universidad de Oviedo, 33006-Oviedo, Spain !
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