The permanent electric dipole moment of holmium monoxide, HoO

The high resolution molecular beam laser-induced fluorescence (LIF) spectrum of the (0, 0) band of the [17.6]7.5-X18.5 system of holmium monoxide, HoO, has been recorded field free and in the presence of a variable static electric field. The rotational constant, B0, and magnetic hyperfine structure constant, h, for the v = 0 levels of the [17.6]7.5 and X18.5 states were obtained by assigning and fitting the field-free spectral features. The Stark shifts and splittings in the LIF spectra were analyzed to produce values for the magnitude of the permanent electric dipole moments, |μ|, of 3.96(6) and 4.80(5) D for [17.6]7.5, v = 0 and X18.5, v = 0, respectively.