Numerical relativistic self-consistent field calculation of electron density and 〈r−3〉 for a number of electron configurations of iron and tin. Application to tin Mössbauer spectroscopy

Results of a relativistic self-consistent field calculation of ‖ψ (0) ‖2 and 〈r−3〉3d and 〈r−3〉5p of Fe and Sn, respectively, in different electron configurations are presented. A comparison is made with often used results of the Hartree–Fock calculations and significant differences are found, which are shown to have implications on the derivation of (ΔR)/R for 57Fe from measurements of an Fe in a rare gas matrix. The results on tin are used to reanalyze a number of determinations of (ΔR)/R and formulas are given expressing the Mössbauer isomer shift and quadrupole splitting of tin in occupation numbers of 5s and 5p shells. These are used in a simple MO model to explain some characteristic features of tin Mössbauer spectra.