Microwave spectrum and molecular constants ofO16O18

Abstract

Measurements of millimeter-wave fine-structure transitions and the $n(J)=0(1)\ensuremath{\rightarrow}2(1)$ rotational transition of $^{16}\mathrm{O}$ $^{18}\mathrm{O}$ have been made with high precision. From analysis of the results the following molecular constants of $^{16}\mathrm{O}$ $^{18}\mathrm{O}$ were obtained: ${B}_{0}=40707.408(10)$ MHz, ${B}_{1}=\ensuremath{-}0.129$ MHz, ${\ensuremath{\lambda}}_{0}=59499.097(43)$ MHz, ${\ensuremath{\lambda}}_{1}=0.05312(80)$ MHz, ${\ensuremath{\mu}}_{0}=\ensuremath{-}238.488(7)$ MHz, ${\ensuremath{\mu}}_{1}=\ensuremath{-}0.000619(116)$ MHz, ${B}_{e}=40931.7(6.9)$ MHz, ${r}_{0}=1.210751(16)$ \AA{}, and ${r}_{e}=1.207429(103)$ \AA{}. The equilibrium values were obtained with the aid of vibration-rotation interaction constants from optical spectroscopy.