Knowledge Bank

A description of the bonding in the ground and low-lying electronic states of the first-row transition metal monohydrides becomes complicated because of the simultaneous involvement of the \ 3d^2, 3d^1$and,tosomeextent, 3d$^n\ 4s$1 4p$^1$electronconfigurationsofthemetal.Thepermanentelectricdipolemomentcanprovideinsightintothiscomplicatedbonding.Herewereportonthedeterminationof\mu e$ for chromium CrD. A number of low-N lines of the X$6\Sigma -A$^6\Sigma$ (0,0) band of chromium monodeuteride, CrD, have been recorded at near the natural line width limit by combining a supersonic molecular beam with high resolution laser excitation spectroscopy. The analysis gives the permanent electric dipole moment of the X$6\Sigma$(v=0) state as 3.51(3)D and 1.152(5)D for the A$6\Sigma$(v=0) state can be measured with higher precision because of some interesting near degeneracies in its level structure. A comparison with theoretical predictions for CrH} \textbf(85), 2850(1986).}'} \textbf{161}, 455(1993).}'} \textbf{110}, 2560(2006).}'} \textbf{121}, 8194(2004).} and experimental values other 3d transition metal monohydrides will be given.