Subject: G94 CI-Singles method

From: Demetrio Antonio da Silva Filho <[email-masked]>
Date: Mon, 17 Jul 2000 12:49:40 -0300

Dear Netters,

I'm in doubt about the CI-Singles method and the number of  single 
substitutions that this method
uses on its calculation.

In Pople's paper (J. B. Foresman, M. Head-Gordon, J. A. Pople and M. J. 
Frisch, Toward a Systematic Molecular Orbital Theory for Excited States, J. 
Phys. Chem. 96, 135 (1992).) the CI-Singles method is
defined as configuration interaction among "all" singly substituted 
determinants. In Gaussian manual,
there is a keyword for this method (NStates) which sets the number of 
states that will be solved.

This keyword (Mstates) sets the number of states used in the CI expansion 
of the wavefunction or
independent of the number used in this keyword all singly substituted 
determinants will
be used?

Thanks in advance,
Demetrio FIlho

_____________________________________

                 Demetrio A. da Silva Filho
                    UNICAMP - IFGW
                     Prédio D - Sala 17
             CEP 13083-970 C.Postal 6165
                    Campinas - SP - Brasil
_____________________________________
"Se não houver frutos, valeu a beleza das flores. Se não houver flores,
valeu a sombra das folhas. Se não houver folhas, valeu a intenção da
semente." Henfil