Subject: Form of Gaussian Basis Sets

From: "Gregory A. Landrum" <[email-masked]>
Date: Fri, 25 Sep 1998 09:12:37 +0200 (DFT)

Hi,

I have found myself in the vaguely uncomfortable position of wanting to
make plots of orbitals from programs like Gaussian and GAMESS which use
gaussian basis sets. I'm planning on adding this functionality to an
existing plotting program, so I need the forms of the basis sets.

So, this is probably a stupid question, but I'm completely fed up with
trying to answer it myself...
I can't seem to find the exact mathematical form of the basis sets used
in these programs.  The only things I can find are equations for the
contracted radial basis functions.  For example:

 \phi_i(r) = \sum_j [ d_{ij} exp(-f_j  a_i  r^2) ]

(where I pull the {d} {f} and {a} values from the Gaussian output file or
the basis set server at EMSL)

I assume that I can combine this with the appropriate cartesian
functions to get the correct *shape* of an orbital, but this doesn't do
anything for me in terms of the *size* (because the resulting orbitals
aren't normalized).  

So, my stupid question is: what is the exact mathematical form of these
gaussian basis sets?  Please don't point me at a book, because
unfortunately our library is not likely to have it.

Thanks in advance for your help.

-greg

-- 
---------------------
Dr. Greg Landrum  ([email-masked])
Institute of Inorganic Chemistry
Aachen University of Technology
Prof.-Pirlet-Str. 1, D-52074 Aachen, Germany
Phone: 049-241-80-7004
Fax: 049-241-8888-288