Theoretical analysis of the electronic structure and molecular properties of the alkali halides. iv. potassium fluoride

Abstract

Results of a recent theoretical investigation of the electronic structure of KF within the SCF-LCAO-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 energy E, equilibrium separation R,, spectroscopic constants ta a,x and B and dipole moment p, are E= -698.68501 a.u., R,=4.18S a.u. (4.1035), w.= 448.5 cm-1 (426.0), cm= 2.484 cm-1 (2.430), S.=0.2686 cm-1 (0.2799), M.=8.6886+ 0.0634(n+i)-0.0001 (v+§)s, and M(exptl)=8.5583+0.0684(t>+e)+0.0002(v+e) 2. The computed dissociation energy (D,HF=0.112 a.u.) has been coupled with estimated correlation and relativisitic contributions (De00=0.065 a.u., D,= -0.001 a.u.), producing a lower limit value, Dll!=0.176 a.u., as compared to £,=0.187. This discrepancy is due to small corrections discussed in the paper. Computed values of the field gradients measured at the potassium nucleus (?K°= -0.6001 a.u.) have been combined with an experimentally determined value of the nuclear quadrupole coupling constant (egK°(RK= -7933.87 kc/sec) to yield for the potassium nuclear quadrupole moments, Q691= 0.0563 ×10 -24 cm2 and Q89K= 0.0685 ×10 -24 cm-1.