Geometry Optimization using CIS and AM1-CI



Dear CCLers,
 I'm studing the geometry of the first excited state using AM1-CI
 (implemented im MOPAC 6) and CIS (implemented in GAUSSIAN 94). I increased
 the size of the CI in AM1-CI and the final geometry changed, as I
 expected.
 But the optimized geometries using CIS method for diferent
 number of excitations used in the calculation were the same. It's a
 particularity associated to the sistem I'm working or it's a particularity
 of the method?
 Does anybody have references of geometry studies of the excited state
 changing the number of excitations and using the CIS method?
 Thanks in advance,
 Demetrio FIlho
 _______________________________________________________________
                 Demetrio A. da Silva Filho
                      UNICAMP - IFGW
                    Predio D - Sala 17
                 CEP 13083-970 C.Postal 6165
                   Campinas - SP - Brazil
 _______________________________________________________________
 "Se nao houver frutos, valeu a beleza das flores. Se nao houver flores,
 valeu a sombra das folhas. Se nao houver folhas, valeu a intencao da
 semente." Henfil