Millimeter and Submillimeter Wave Rotational Spectrum and Centrifugal Distortion Effects of HDO

Abstract

The rotational spectrum of HDO in the ground vibrational state has been studied in the millimeter and submillimeter microwave region. Twenty‐one previously unreported transitions have been measured and assigned. These data have been combined with previous measurements on HDO for a centrifugal distortion analysis based entirely on microwave measurements. In the analysis distortion effects through P¹⁰ are included, although only a partial set of terms in P⁸ and P¹⁰ is found to be necessary. The results for the rotational constants, quartic and sextic distortion constants are (in megacycles per second): ${}^A{\text{=701\hspace{0.17em}931.50 ± 0.22,\hspace{0.17em}}}^B{\text{=272\hspace{0.17em}912.60 ± 0.11,\hspace{0.17em}}}^C{\text{=192\hspace{0.17em}055.25 ± 0.10,\hspace{0.17em}Δ}}_J{\text{= 10.8375 ± 0.0058,\hspace{0.17em}Δ}}_{\mathrm{JK}}{\text{=34.208 ± 0.036,\hspace{0.17em}Δ}}_K{\text{=377.078 ± 0.026,\hspace{0.17em}δ}}_J{\text{=3.6471 ± 0.0014,\hspace{0.17em}δ}}_K{\text{=63.087 ± 0.035,\hspace{0.17em}H}}_J{\text{=1.128 × 10}}^{\text{−3}}{\text{± 0.099 × 10}}^{\text{−3}}{\mathrm{,\hspace{0.17em}H}}_{\mathrm{JK}}{\text{=7.344 × 10}}^{\text{−2}}{\text{± 0.092 × 10}}^{\text{−2}}{\mathrm{,\hspace{0.17em}H}}_{\mathrm{JK}}{\text{=−2.740 × 10}}^{\text{−1}}{\text{± 0.022 × 10}}^{\text{−1}}{\mathrm{,\hspace{0.17em}H}}_K{\text{=1.4651 × 10}}^0{\text{± 0.0027 × 10}}^0{\mathrm{,\hspace{0.17em}h}}_J{\text{=6.546 × 10}}^{\text{−4}}{\text{± 0.150 × 10}}^{\text{−4}}{\mathrm{,\hspace{0.17em}h}}_{\mathrm{JK}}{\text{=3.096 × 10}}^{\text{−2}}{\text{± 0.037 × 10}}^{\text{−2}},$ and $h_K{\text{=5.549 × 10}}^{\text{−1}}{\text{± 0.053 × 10}}^{\text{−1}}.$