On the low-lying states of WO A comparison with CrO and MoO》.pdfVIP

Volume 118, number 2 CHEMlCAL PHYSICS LETTERS 19 July 1985 ON THE LOW-LYTNG STATES OF WO: A COMPAFUSON WITH CrO AND MoO Constance J. NELIN ’ Analatom Inc. 253 Humboldr Cow-r, Sunnywale, CA 94089. USA and Charles W. BAUSCHLICHER Jr. NASA Ames Research Cenrer. Mofferr Field CA 94035, USA Received 20 March 1985; in final form 11 April 1985 We have investigakd the four low-lying stales of WO and compared Thesewith similar stales of CrO and MOO. For all these syskms the ground state is ‘II. but the ordering of Lhe upper states is different between WO and either G-0 or MoO. Tbc dtffercnce m the state ordering arises in part from the fact that in WO all of the states are formed from W+ in a d’s’ configuration. whereas in both G-0 and MoO some states are formed from the d5 configuration and others from the d4s’ wnftguration. 1. Introduction 5X+ ‘II and 7 Z+. These high spin states arise from the iage d-d exchange, which favors the high spin In previous studies [l-3], the nature of the bond- coupling of the d electrons_ We find that for all three ing in selected first- and second-row transition metal systems the ground state is 511. This state, while being oxides has been investigated. It was found that the rather ionic, M@Oq-, where 4 = OSe, also contains bonding ranged from being purely ionic, e.g., 0.10, to a covalent bond formed between the met