State-of-the-art ab initio calculations of the molecular electric quadrupole moments of hydrogen fluoride

Highly accurate values of the molecular electric quadrupole moment (Theta) referring to the centre-of-mass of hydrogen fluoride have been determined b y means of sophisticated ab initio methods. Our best equilibrium result-obt ained as the full configuration interaction basis-set limit value augmented with a semi-relativistic correction-is Theta (e) = (1.7121 +/-0.0006) a.u. = (7.681 +/-0.003) x 10(-40) C m(2). The corresponding rovibrationally corr ected quadrupole moment Theta (v=0,J=1) = (1.7691 +/-0.0006) a.u. = (7.937 +/-0.003) x 10(-40) C m(2) compares very favourably with the experimental v alue Theta (v=0,J=1) = (7.87 +/-0.10) x 10(-40) C m(2). (C) 2001 Elsevier S cience B.V. All rights reserved.