THEORETICAL-STUDY OF THE PSI2 RADICAL

G2 methodology has been used to characterize minima on both doubler an d quartet potential energy surfaces of the PSi2 radical system; We fou nd that for states with doubter spin multiplicity the most stable isom er is the cyclic (2)A(1). Linear isomers lie more than 24 kcal/mol abo ve in energy. For the quarters the most stable state isomer is the cyc lic (4)A(2), and the most stable linear isomer, i.e., Si-Si-P((4)Z(-)) , lies 10.68 kcal/mol higher in energy. The structural features of the various isomers characterized have been rationalized in terms of the bonding features of the molecular orbitals involved.