The visible spectrum of zirconium dioxide, ZrO2.

The electronic spectrum of a cold molecular beam of zirconium dioxide, ZrO(2), has been investigated using laser induced fluorescence (LIF) in the region from 17,000 cm(-1) to 18,800 cm(-1) and by mass-resolved resonance enhanced multi-photon ionization (REMPI) spectroscopy from 17,000 cm(-1)-21,000 cm(-1). The LIF and REMPI spectra are assigned to progressions in the Ã(1)B(2)(ν(1), ν(2), ν(3)) ← X̃(1)A(1)(0, 0, 0) transitions. Dispersed fluorescence from 13 bands was recorded and analyzed to produce harmonic vibrational parameters for the X̃(1)A(1) state of ω(1) = 898(1) cm(-1), ω(2) = 287(2) cm(-1), and ω(3) = 808(3) cm(-1). The observed transition frequencies of 45 bands in the LIF and REMPI spectra produce origin and harmonic vibrational parameters for the Ã(1)B(2) state of T(e) = 16,307(8) cm(-1), ω(1) = 819(3) cm(-1), ω(2) = 149(3) cm(-1), and ω(3) = 518(4) cm(-1). The spectra were modeled using a normal coordinate analysis and Franck-Condon factor predictions. The structures, harmonic vibrational frequencies, and the potential energies as a function of bending angle for the Ã(1)B(2) and X̃(1)A(1) states are predicted using time-dependent density functional theory, complete active space self-consistent field, and related first-principle calculations. A comparison with isovalent TiO(2) is made.