15min:

DALE J. BRUGH AND RICHARD D. SUENRAM, National Institute of Standards and Technology, Optical Technology Division, Gaithersburg, MD 20899-8441; WALTER J. STEVENS, National Institute of Standards and Technology, Physical and Chemical Properties Division, Gaithersburg, MD 20899-8380.

The pure rotational spectrum of the asymmetric top ZrO₂ has been collected using a Fourier transform microwave spectrometer that employed a laser ablation molecular beam source. Four rotational transitions for each of five Zr¹⁶O₂ isotopomers have been recorded. The rotational constants of the ⁹⁰Zr¹⁶O₂ isotope were determined to be A = 19881.352 \pm 0.068 MHz, B = 7693.895 \pm 0.021 MHz, and C = 5533.111 \pm 0.036 MHz. The r₀ structure was determined to possess a Zr-O bond length of 1.7710 \pm 0.0007 Å, and an O-Zr-O bond angle of 108.11 \pm 0.08^\circ. The electric dipole moment has been measured for the ⁹⁰Zr¹⁶O₂ isotope and found to be µ_b = 7.80 \pm 0.02 Debye. The nuclear quadrupole hyperfine structure for the ⁹¹Zr¹⁶O₂ isotope has also been recorded and analyzed, yielding _aa = 115.94 \pm 0.16 MHz, _bb = -37.55 \pm 0.33 MHz, and _cc = -78.39 \pm 0.16 MHz. High-level density functional theory calculations have yielded a structure that agrees well with the values determined experimentally.