The permanent electric dipole moments and magnetic g_e factors of neodymium monoxide

Stark and Zeeman spectra of the [16.7] 3-X4 transition of neodymium monoxide (NdO) have been obtained at a resolution of less than 40 MHz. Analysis of the Stark spectra yielded permanent electric dipole moments μel of 3.742(16) and 3.369 (13) D for the [16.7]3 and X4 states, respectively. The ground state value μel is compared to that of isovalent uranium monoxide (UO) and those of other lanthanide monoxides using a molecular orbital description. Analysis of the Zeeman spectra yielded magnetic ge factors of 2.084(6) and 2.178(8) for the J=3 and 4 rotational levels, respectively, of the [16.7]3 state and a ge factor of 2.116(6) for the X4 state. A comparison with the ge factor expected from the ab initio [Allouche, J. Chem. Phys. 124, 184317 (2006)] and the ligand field theory [P. Carette and A. Hocquet, J. Mol. Spectrosc. 131, 301 (1988)] predictions for the X4 ground state is given.