Subject: Re:summary intermolecular interactions

From: Gabriele Valerio <[email-masked]>
Date: Fri, 20 Mar 1998 18:37:03 +0100

Dear Mark, and CCL netters,

I am sorry for sending a late reply to your question about ab initio
calculation of the intermolecular interaction, after your recently
posted summary.

Gianinetti, Raimondi and Tornaghi have recently adapted the Roothan
equations to exclude the basis set superposition error from
intermolecular interactions (ref. Int. J. Quantum Chem. vol. 60, 157-166
(1996)). The calculation produces BSSE free Hartree-Fock energy for
interacting fragments, without any a posteriori corrections. The
computational cost is not appreciably higher than an ordinary HF.
The method has benn implemented in latest version of GAMESS-USA by
Famulari.

In some cases the BSSE error can be larger than the correlation energy. 

Best wishes

		 Guido Raos and Gabriele Valerio

-- 
Gabriele VALERIO
Politecnico di Milano		Tel: ++39-(0)2-23993051
Dipartimento di Chimica		Fax: ++39-(0)2-23993080
via Mancinelli, 7
20131 Milano (ITALY)
mailto:[email-masked]