Relativistic double-zeta, triple-zeta, and quadruple-zeta basis sets for the lanthanides La–Lu

Relativistic basis sets of double-zeta, triple-zeta, and quadruple-zeta quality have been optimized for the lanthanide elements La-Lu. The basis sets include SCF exponents for the occupied spinors and for the 6p shell, exponents of correlating functions for the valence shells (4f, 5d and 6s) and the outer core shells (4d, 5s and 5p), and diffuse functions, including functions for dipole polarization of the 4f shell. A finite nuclear size was used in all optimizations. The basis sets are illustrated by calculations on YbF. Prescriptions are given for constructing contracted basis sets. The basis sets are available as an internet archive and from the Dirac program web site, http://dirac. chem. sdu. dk. © 2010 The Author(s)

The [557]-X²∑⁺ and [561]- X²∑⁺ bands of ytterbium fluoride,¹⁷⁴YbF

The [557] - X2Σ+(v = 0, 1, 2, 3) and the [561] - X2Σ+ (v = 2) visible electronic transitions of YbF have been recorded at a near-natural linewidth spectral resolution using both supersonically cooled and buffer-gas cooled beams. The 174YbF isotopologue spectral features were analyzed to produce a new set of spectroscopic parameters for the X2Σ+(v = 2), X2Σ+(v = 3), [557], and [561] states. This study will facilitate ongoing work to produce ultracold YbF molecules by laser cooling in order to improve measurements of the electron’s electric dipole moment