Knowledge Bank

The lowest $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Delta , \mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma +$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi$ states of VC are investigated using {ab initio} multireference single find double excitation configuration interaction (MRSD-CI)-The dominant electronic configuration for the $X2\Delta$ gound state, the $A2\Sigma +$ and $A2\Pi$ states are $8\sigma 23\pi x2 3\pi y2 1\delta xy\mathrm{\backslash dag} ,9\sigma \mathrm{\backslash dag} 3\pi x2 3\pi y2$ and $9\sigma 2 3\pi x2 3\pi y1$ respectively. The $A \mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma +\leftarrow X2\Delta$ transition is predicted to occur around $9056cm-1$ while the $A \mathrm{<mrow\; data-mjx-texclass="ORD">,2</mrow>}\Pi +\leftarrow X2\Delta$ is estimated to lie around $16000cm-1$. The spectroscopic parameters, $Re,\omega e,\omega eXe,Be,\alpha e,\mu e,d\mu /dr|e$ and the hyperfine coupling constants ($b1bF$ and c) are also computed for these three states. These are compared with the preliminary experimental results Morese et al. Similar extensive MRSD-CI calculations yield hyperfine coupling constants for isoelectronic TiN molecule that are in good agreement with the experimental results of stiemle {et al}.