First principles calculation of Mössbauer isomer shift

Mössbauer spectroscopy is a widely used analytic tool which provides information about local electronic structure of solid materials on an atomic scale. The isomer shift of resonance nuclear γ transition is a sensitive parameter which depends on the charge and spin state of the resonating atom as well as on its chemical environment. Theory underlying the isomer shift is reviewed and its connection to the local electronic structure is discussed. A review of advances made in the ab initio   calculation of isomer shift is presented. The importance of careful calibration of the parameters of nuclear γ transitions on the basis of high-level quantum chemical calculations with the inclusion of both relativistic effects and electron correlation is underlined. With the help of accurate theoretical calculations of the isomer shift over a wide range of chemical environments deeper understanding of a relationship between the observed spectroscopic parameters and the electronic structure of materials will be gained.