CALCULATED VIBRATIONAL STRUCTURE OF THE FIRST BAND OF THE PHOTOELECTRON-SPECTRUM OF HO2- AND THE ELECTRON-AFFINITY OF HO2

The vibrational structure of the first band of the photoelectron (PE) spectrum of HO2- and DO2- has been calculated on the basis of (slightl y modified) ab initio potentials. The best agreement with the experime ntal spectrum of HO2- is obtained for a vibrational temperature of ca. 600 K. ''Peak D'', which has been under debate in earlier work, is co mposed of two transitions, with the ''hot'' transition 3(1)(1) being m ore intense than the adiabatic transition. Since the nu(2) bending mod e of DO2 has significant OO stretching character, the vibrational stru cture of the PE spectrum of DO2- is more complex than that of HO2-. La rge-scale RCCSD(T) calculations of the equilibrium electron affinity o f HO2 yield 1.058 eV which agrees with the experimental value of 1.044 +/- 0.020 eV.