Calibration of 119Sn isomer shift using ab initio wave function methods.

Area of Science:

• Nuclear physics
• Computational chemistry
• Materials science

Background:

• The isomer shift of the (119)Sn nucleus is a sensitive probe of its electronic environment.
• Accurate calibration of the isomer shift is crucial for interpreting experimental data.

Purpose of the Study:

• To calibrate the isomer shift for the 23.87 keV M1 resonant transition in the (119)Sn nucleus using ab initio calculations.
• To validate the calibration approach by studying the (119)Sn isomer shift in CaSnO(3) perovskite under pressure.

Main Methods:

• Ab initio calculations, including Hartree-Fock (HF) and second-order Møller-Plesset (MP2) methods.
• Statistical analysis to assess the impact of electron correlation effects.
• Application of the calibrated method to analyze experimental pressure-dependent isomer shift data.

Main Results:

• Calibration constants obtained from HF and MP2 calculations show good agreement with previous values.
• Electron correlation effects are shown to be important for accurate calibration.
• The methodology accurately describes experimental (119)Sn isomer shift variations in CaSnO(3) under pressures up to 36 GPa.

Conclusions:

• The ab initio calculation approach provides a reliable method for calibrating the (119)Sn isomer shift.
• The validated methodology can accurately describe pressure-induced changes in the isomer shift of tin-containing materials.