Knowledge Bank

High resolution optical spectroscopy has been used to study a molecular beam of molybdenum carbide, MoC. The $Re(0)(\nu =18612.978\backslash wn)$ and $Qfe(1)(\nu =18611.872\backslash wn)$ branch features of the (0,0) $[18.6]3\Pi 1-X3\Sigma -$ system of $\mathrm{<mrow\; data-mjx-texclass="ORD">98</mrow>}MoC$ were analyzed using Stark spectroscopy. Electric field induced splitting in the laser induced fluorescence (LIF) spectra was analyzed to measure permanent electric dipole moments of 2.69(2)D and 6.32(20)D for the $[18.6]3\Pi 1$ and $X3\Sigma -$ states, respectively. Excited state hyperfine structure has been observed for the first time in $\mathrm{<mrow\; data-mjx-texclass="ORD">95</mrow>}MoC$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">97</mrow>}MoC$. Experimental results will be compared to theoretical predictions, } \underline{\textbf{106}}, 8093 (1997).} and the electronic structure will be discussed using a molecular orbital correlation model. The MoC dipole moments will be compared with those of other transition metal monocarbides. An interesting observation is that the \textit{ab initio} calculations for second row transition metal monocarbides are more reliable than predictions for the first row carbides.