OPTICAL STARK SPECTROSCOPY OF NICKLE MONOHYDRIDE, NiH\thanks{Supported by NSF(TCS-ASU).}

J.A. Gray, S.F. Rice and R.W. Field, J. Chem. Phys., 82,4717 (1985).C.V. Diaconu, A.E. Cho, J.D. Doll and D.L. Freeman, J. Chem. Phys., 121, 10026 (2004).Author Institution: Chemistry and Biochemistry, Arizona State University, Tempe, AZ USA 85287Sometimes ago the MIT group analyzed the Doppler limited optical Stark Spectrum for the $B^{2}\Delta_{5/2}$-$X^{2}\Delta_{5/2}$(1,0) $Q$(2.5) line of NiH to determine the permanent electric dipole moments, $nu$, of 2.4$\pm$0.1 D and 0.3$\pm$0.1 D for the $X^{2}\Delta_{5/2}$ and $B^{2}\Delta_{5/2}$ 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$0.02 D and 0.36$\pm$0.02 D for the $X^{2}\Delta_{5/2}$ and $B^{2}\Delta_{5/2}$ states, respectively. The observed trends in the $nu$ value for the ground state of the first row transition metal monohydrides will be rationalized