The visible spectrum of zirconium dioxide, ZrO2

The electronic spectrum of a cold molecular beam of zirconium dioxide, ZrO2, 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 ÃB21(ν1, ν2, ν3) ← X̃A11(0, 0, 0) transitions. Dispersed fluorescence from 13 bands was recorded and analyzed to produce harmonic vibrational parameters for the X̃A11 state of ω1 = 898(1) cm−1, ω2 = 287(2) cm−1, and ω3 = 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 ÃB21 state of Te = 16 307(8) cm−1, ω1 = 819(3) cm−1, ω2 = 149(3) cm−1, and ω3 = 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 ÃB21 and X̃A11 states are predicted using time-dependent density functional theory, complete active space self-consistent field, and related first-principle calculations. A comparison with isovalent TiO2 is made.