Determination of the 23Na nuclear quadrupole moment from molecular data for NaF and NaCl

Abstract

High-level correlated calculations of the electric field gradient at Na in NaF and NaCl have been carried out with large basis sets of Gaussian functions. The singles and doubles coupled-cluster results corrected noniteratively for the effects of three-body clusters have been combined with microwave spectroscopic data to yield a new ‘molecular’ value of the nuclear quadrupole moment of 23Na, Q( 23Na) = 104 mb, whose uncertainty is expected to be not worse than about 1%. The present ‘molecular’ result for Q( 23Na) lies between the two currently most reliable values obtained from atomic spectra (107.1(2.1) mb) and muonic experiments (100.6(2.0) mb).