Knowledge Bank

Sometimes ago the MIT group analyzed the Doppler limited optical Stark Spectrum for the $B2\Delta 5/2$-$X2\Delta 5/2$(1,0) $Q$(2.5) line of NiH to determine the permanent electric dipole moments, $nu$, of 2.4$\pm$0.1Dand0.3$\pm$0.1 D for the $X2\Delta 5/2$ and $B2\Delta 5/2$ states, respectively.}\ The ground state value of $nu$ is routinely predicted to assess the quality of electronic structure predictions.}\ In an effort to reduce the uncertainty in the experimental value of $nu$ we have analyzed the optical Stark spectrum of the $Q$(2.5) and $P$(3.5) of a molecular beam sample. A molecular beam was generated by skimming the output of a laser ablation/supersonic expansion. The dipole moments were determined to be 2.44$\pm$0.02Dand0.36$\pm$0.02 D for the $X2\Delta 5/2$ and $B2\Delta 5/2$ states, respectively. The observed trends in the $nu$ value for the ground state of the first row transition metal monohydrides will be rationalized.