Theoretical Analysis of the Electronic Structure and Molecular Properties of the Alkali Halides. IV. Potassium Fluoride

摘要

Results of a recent theoretical investigation of the electronic structure of KF within the SCFndash;LCAOndash;MO framework are discussed, giving special emphasis to the evaluation of various molecular properties. Computed values (followed by experimental values in parentheses) for the total energyE, equilibrium separationRe, spectroscopic constantsohgr;e, ohgr;exe, andBe, and dipole momentmgr;, areEthinsp;equals;thinsp;minus;698.68501a.u.,Rethinsp;equals;thinsp;4.188a.u.lpar;4.1035rpar;,ohgr;ethinsp;equals;thinsp;448.5cmminus;1lpar;426.0rpar;,ohgr;exethinsp;equals;thinsp;2.484cmminus;1lpar;2.430rpar;,Bethinsp;equals;thinsp;0.2686cmminus;1lpar;0.2799rpar;,mgr;ugr;thinsp;equals;thinsp;8.6886thinsp;plus;thinsp;0.0634lpar;ugr;thinsp;plus;thinsp;12rpar;thinsp;minus;thinsp;0.0001lpar;ugr;plus;12rpar;2, andmgr;ugr;lpar;exptlrpar;thinsp;equals;thinsp;8.5583thinsp;plus;thinsp;0.0684lpar;ugr;thinsp;plus;thinsp;12rpar;thinsp;plus;thinsp;0.0002lpar;ugr;thinsp;plus;thinsp;12rpar;2. The computed dissociation energylpar;DeHFthinsp;equals;thinsp;0.112a.u.rpar;has been coupled with estimated correlation and relativisitic contributionslpar;Decorrthinsp;equals;thinsp;0.065a.u.,Derelthinsp;equals;thinsp;minus;0.001a.u.rpar;, producing a lower limit value,Decalcthinsp;equals;thinsp;0.176a.u., as compared toDeexptlthinsp;equals;thinsp;0.187. This discrepancy is due to small corrections discussed in the paper. Computed values of the field gradients measured at the potassium nucleuslpar;qK0thinsp;equals;thinsp;minus;thinsp;0.6001a.u.rpar;have been combined with an experimentally determined value of the nuclear quadrupole coupling constantlpar;eqK0QKthinsp;equals;thinsp;minus;thinsp;7933.87kcsol;secrpar;to yield for the potassium nuclear quadrupole moments,Q39Kthinsp;equals;thinsp;0.0563thinsp;times;thinsp;10minus;24cm2andQ41Kthinsp;equals;thinsp;0.0685thinsp;times;thinsp;10minus;24cm2.