Study of HD17O spectrum. Theory and experiment

Abstract

A spectrum of HD¹⁷O in the region between 5 480 and 6 400 ${\text{cm}}^{-1}$ recorded in Tomsk is reported. In this region 4292 lines are observed belonging to 7 water isotopologues: 536 lines – H${}_2{}^{16}$O 1019 – HD¹⁶O, 122 – D${}_2$ ${}^{16}$O, 447 – H${}_2{}^{17}$O 458 – HD¹⁷O, 151 – H${}_2^{18}$O, 181 – HD¹⁸O. A new potential energy surface (PES) of HD¹⁶O is obtained by fitting to empirical energy levels. This PES, with a diagonal Born–Oppenheimer correction (DBOC), is used to compute the HD¹⁷O spectrum. Pseudo-experimental isotopologue-extrapolation energy levels of HD¹⁷O are constructed using the method of Polyansky et al (MNRAS 466, 1363 (2017)). Assignment of the measured spectrum is conducted: 68 % of the lines can be assigned using assignments from previously published work. The remaining lines are assigned using the pseudo-experimental energy levels procedure. We compare the calculated pseudo-experimental values of energy levels with both existing 1285 experimental levels of HD¹⁷O and the 152 newly determined in this work energy levels. The standard deviation of levels with low J (up to J=10) is about 0.007 ${\text{cm}}^{-1}$ in both cases. Energy levels from both pseudo-experimental and variationally calculated are also compared with newly measured HD¹⁷O lines above 10 000 ${\text{cm}}^{-1}$.