Nuclear quadrupole moments from molecular microwave data: The quadrupole moment of Rb-85 and Rb-87 nuclei and survey of molecular data for alkali-metal nuclei

The "molecular'' values of the quadrupole moment of the Rb and Na nuclei ha ve been obtained by using spectroscopic values of nuclear coupling constant s and high-level-correlated relativistic calculations of the electric-field gradients in fluorides and chlorides. The recommended value for the Rb-85 nucleus which follows from the present study is about 276 mb, with expected error bars of the order of about 1 mb. This value agrees with the atomic s pectroscopy data, and suggests that the quadrupole coupling constant measur ed for the RbCl molecule is in error. The present calculations for Na-23 co nfirm the earlier molecular result for its electric quadrupole moment, and combined with recent atomic calculations lead to the recommended value in t he range 104-105 mb. The molecular results for nuclear quadrupole moments o f the alkali-metal nuclei are reviewed leading to a list of the correspondi ng recommended values. [S1050-2947(99)07510-1].