Electronic states of Pt2

摘要

Complete active space MCSCF (CASSCF) followed by firsthyphen;order configuration interaction (FOCI) calculations are carried out on lowhyphen;lying electronic states of Pt2. The spinndash;orbit interaction is introduced through a relativistic configuration interaction method. Twentyhyphen;two lowhyphen;lying ohgr;ndash;ohgr; states withTe15thinsp;000 cmminus;1and 11 lgr;ndash;sstates withTe3189 cmminus;1are found. The nature of all these electronic states is discussed. The calculatedRevalues of all the electronic states are between 2.4 and 2.6 Aring;. The spinndash;orbit effects are found to be significant for the electronic states of Pt2. The CASSCF/FOCI dissociation energies of the strongesthyphen;bound states in the absence of spinndash;orbit interaction are calculated to be about 2.3 eV. The spinndash;orbit interaction decreases theDe. The dissociation energies of the strongesthyphen;bound states in the presence of spinndash;orbit interaction are about 1.85ndash;1.95 eV.