Subject: summary: UHF correlation energy

From: Vitaly Rassolov <[email-masked]>
Date: Mon, 1 Jun 1998 16:12:41 -0500 (CDT)

Dear CCLers:

A while ago I asked about the availability of atomic correlation energy
based on UHF wave functions.  Strictly speaking, it is the UHF-based
correlation energy which is modeled in traditional DFT theory, so the
issue seem to be important.  It turns out that nobody had tried to find
the UHF corelation energy, as far as CCLers know.  One of the possible
reasons is that one can estimate the UHF Ecorr. by subtracting the
difference (E(rohf)-E(uhf)) from the ROHF-based corr. energy.  This
difference is rather small and in most cases is comparable to the error in
the correlation energy itself.

Below is the summary of responses:

From: Pablo Vitoria Garcia <[email-masked]>
Dear Vitaly,

You may find these references useful:

Rosciszewsli,K. "Simple Empirical Formulas and good quality estimatios for
electron correlation energies of molecules and molecular clusters: first
row atom molecules", International Jourl of Qunatum Chemistry, (1996),
58(5), 471-485

Kristyan, S. "Inmediate estimation of correlation energy for molecular
systems from the partial charges on atoms in the molecule", Chem. Phys.,
(1997), 224(1), 33-51

*****

From: Jaouad El-Bahraoui <[email-masked]>

can you summerized to the CCL please.
many thanks

*****

Vitaly Rassolov
Chemistry Department
Northwestern University
[email-masked]