We report a systematic investigation, using state-of-the -art techniques, on the electronic and optical properties of two crystals of alkaline-earth-metal fluorides, namely MgF2 and SrF2. For these crystals we present Density Functional Theory (DFT), Many-Body Perturbation Theory (MBPT) and Bethe-Salpeter-Equation (BSE) calculations. We calculate a variety of properties, namely ground-state energies, band-energy gaps, and optical absorption spectra with the inclusion of excitonic effects. The data are obtained with a high degree of convergence regarding all the bulk electronic and optical properties. It turns out that bulk MgF2 has distinguished ground-stateand excited-state properties with respect to the other fluorides. Bulk SrF2 is closer to the other members of the alkaline-earth-metal fluorides family in in contrast to MgF2 with thelighter cation. The nature of the fundamental gaps and estimates of the self-energy and excitonic effects for the two compounds are presented and discussed in detail. The results of the present research are in good accordance with those known from measurements or theoretical-computational treatments.
Electronic and optical properties of alkaline-earth-metal fluoride crystal including many-body effects: a comparative study on MgF2 and SrF2
Giancarlo Cappellini;
2022-01-01
Abstract
We report a systematic investigation, using state-of-the -art techniques, on the electronic and optical properties of two crystals of alkaline-earth-metal fluorides, namely MgF2 and SrF2. For these crystals we present Density Functional Theory (DFT), Many-Body Perturbation Theory (MBPT) and Bethe-Salpeter-Equation (BSE) calculations. We calculate a variety of properties, namely ground-state energies, band-energy gaps, and optical absorption spectra with the inclusion of excitonic effects. The data are obtained with a high degree of convergence regarding all the bulk electronic and optical properties. It turns out that bulk MgF2 has distinguished ground-stateand excited-state properties with respect to the other fluorides. Bulk SrF2 is closer to the other members of the alkaline-earth-metal fluorides family in in contrast to MgF2 with thelighter cation. The nature of the fundamental gaps and estimates of the self-energy and excitonic effects for the two compounds are presented and discussed in detail. The results of the present research are in good accordance with those known from measurements or theoretical-computational treatments.
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