ON THE ELECTRONIC-STRUCTURE OF MOO - SPIN-POLARIZED DENSITY-FUNCTIONAL CALCULATIONS OF SPECTROSCOPIC PROPERTIES OF LOW-LYING QUINTET, TRIPLET, AND SEPTET STATES

Density functional theory (DFT) calculations for the ground state and four excited quintet, two septet, and two triplet states of the molybdenum oxide molecule are reported. Equilibrium geometries and other spectroscopic constants are determined for these states and compared both with recent spectroscopic measurements and other theoretical calculations, where available. Experimental assignments of the 5PI ground state and excited 5SIGMA+, 5SIGMA-, 5DELTA, and B' 5PI states are confirmed; also candidates for low-lying triplet 3DELTA and 3SIGMA- and septet 7PI and 7SIGMA+ are presented. Theoretical calculations for 5SIGMA-, B' 5PI, and 3SIGMA- states are reported for the first time. The results are in many cases in better agreement with experiment than are other calculations, already at the simplest level of approximation within DFT, which confirms that this method is a useful tool for investigation of transition-metal compounds. (C) 1994 John Wiley & Sons, Inc.