CCL:G: how G03 builds promolecule density for Hirshfeld population analysi

 Sent to CCL by: "Ol  Ga" [eurisco1:+:pochta.ru]
 Dear  Alvaro!
 After your additional comments I understood what you want. It is not necessary
 to do atomic calculations explicitly to determine Hirshfeld charges because the
 program Gaussian do necessary calculations internally. It is the reason why you
 didnt notice the atomic calculations. I dont know technical details about
 normalization etc. I dont have Gaussian 03 Programmers reference. And I dont
 know is the calculation atomic or not.
 But I know that in the article
 F. L. Hirshfeld, Bonded-Atom Fragments for Describing
 Molecular Charge Densities, Theoret. Claim. Acta (Berl.) 44, 129-138 (1977)
 the promolecule density at point r is written algebraically  as
 ro_pro(r)=sum_i[ro_i_at(r)]
 where the functions p_i_at are suitably positioned, _spherically averaged
 ground-state atomic
 densities_ p. 130
 Additional technical details you can see in
 1) Roman F. Nalewajski, Robert G. ParrInformation theory, atoms in molecules,
 and molecular similarity, PNAS August 1, 2000 vol. 97 no. 16 8879-8882
  http://www.pnas.org/content/97/16/8879.full
 2) Robert G. Parr, Paul W. Ayers, and Roman F. Nalewajski, What Is an Atom in a
 Molecule?
  J. Phys. Chem. A 2005, 109, 3957-3959, 3957
 I want to hope that  my modest comments are  useful.
 Sincerely,
 Ol Ga
 ----- Original Message -----
 > From: A VM fray.gory ~~ gmail.com
 To: Ga, Ol
 Sent: Friday, August 22, 2008 8:12 PM
 Subject: CCL:G: how G03 builds promolecule density for Hirshfeld population
 analysi
 Dear  Ol Ga,
 First, thanks so much by your answer.
 If the program does not make atomic calculations to
 have the density of isolated atoms, then these
 densities come from a database. Here is my question,
 how is the database done?
 Alvaro
 On 8/22/08, Ol Ga eurisco1*pochta.ru <owner-chemistry.:.ccl.net> wrote:
 Sent to CCL by: "Ol  Ga" [eurisco1#%#pochta.ru]
 Dear Alvaro!
 It is necessary to type 6D 10F in route section.
 It is not necessary to do atomic calculations. There are my answers if I
 understand you.
 F. DE PROFT, ALSENOY, PEETERS, LANGENAEKER, GEERLINGS
 Atomic Charges, Dipole Moments, and Fukui Functions
 Using the Hirshfeld Partitioning of the Electron Density, J Comput Chem 23:
 11981209, 2002
 the density constructed from superimposing the isolated electron densities of
 the atoms present at their position in
 the molecule (the so-called promolecule density) p. 1199
 This approach is based on the idea to describe the molecule by dividing it into
 atoms and see how these atoms differ from the
 isolated atoms.  p. 1199
 Sincerely,
 Ol Ga
 ----- Original Message -----
 > From: Alvaro Vazquez vama*o*xanum.uam.mx
 To: Ga, Ol
 Sent: Friday, August 22, 2008 3:25 AM
 Subject: CCL:G: how G03 builds promolecule density for Hirshfeld population
 analysis?
 Dear CCL readers,
 I found the option IOP(6/79=1) to get Hirshfeld charges in Gaussian03.
 I cannot notice the atomic calculations, how the promolecule density is build?
 Is there a specific basis set to work with that?
 Thanks in advance
 Alvaro