Data complementary to the paper:
Molecular Electronic Density Fitting Using Elementary Jacobi
Rotations under Atomic Shell Approximation (ASA)
Institute of Computational Chemistry, University
of Girona, Girona 17071, Catalonia, Spain
ABSTRACT
Fitted electron density functions
constitute an important step in quantum similarity studies. This fact not only
is presented in the published papers concerning quantum similarity measures
(QSM), but also can be associated to the success of the developed fitting
algorithms. As has been demonstrated in previous work, electronic density can
be accurately fitted using the atomic shell approximation (ASA). This
methodology expresses electron density functions as a linear combination of
spherical functions, with the constraint that expansion coefficients must be
positive definite, in order to preserve the statistical meaning of the density
function as a probability distribution. Recently, an algorithm based on
elementary Jacobi rotations (EJR) technique was proven as an efficient electron
density fitting procedure. In the preceding studies, the EJR algorithm was
employed to fit atomic density functions, and subsequently molecular electron
density was built in a promolecular way as a simple sum of atomic densities.
Following previously established computational developments, in this paper the
fitting methodology is applied to molecular systems. Although promolecular
approach is sufficiently accurate for quantum QSPR studies, some molecular
properties, such as electrostatic potentials, cannot be described using such
level of approximation. The purpose of the present contribution is to
demonstrate that using the promolecular ASA density function as starting point,
it is possible to fit ASA-type functions easily to the ab initio molecular electron density. A comparative study of
promolecular and molecular ASA density functions for a large set of molecules
using a fitted 6-311G atomic basis set is presented and some application
examples are also discussed.
Available tables for 1S-type Gaussian basis for
atoms H to Ar, fitted from a 6-311G
basis set.
Other related worldwide web sites of ASA density functions.
Last updated: 17 March 2000, by Lluís Amat