ANH LE AND TIMOTHY C. STEIMLE, Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287; LEONID SKRIPNIKOV AND ANATOLY V. TITOV, Petersburg Nuclear Physics Institute, Gatchina, 188300, Russia and Quantum Mechanics Division, St. Petersburg State University, St. Petersburg 198904, Russia .
The identification of HfF+ as a possible candidate for a d e measurement has stimulated new interest in the spectroscopy of both HfF+ , , and neutral HfF a, . Studies of the neutral are relevant because photoionization schemes can be used to produce the cations. More importantly, computational methodologies used to predict the electronic wavefunction of HfF+ can be effectively assessed by making a comparison of predicted and experimental properties of the neutral, which are more readily determinable. The (1,0)[17.9]2.5 - X 2 3/2 band of hafnium monofluoride (HfF) has been recorded using high-resolution laser-induced fluorescence spectroscopy both field-free and in the presence of a static electric field. The field-free spectra of 177HfF, 179HfF, and 180HfF were model to generate a set of fine and hyperfine parameters for the X 2 3/2 (v=0) and [17.9]2.5 (v=1) states. The observed optical Stark shifts for the 180HfF isotopologue were analyzed to produce the molecular frame electric dipole moments of 1.66(1)D and 0.419(7)D for the X 2 3/2 and [17.9]2.5 states, respectively. A two-step ab initio calculation consisting of a two-component generalized relativistic effective core potential calculation (GRECP) followed by a restoration of the proper four-component wavefunction was performed to predict the properties of ground state HfF.