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Simple accuracy boost for core excitation calculations

October 19th, 2020 by Patrick Rinke
Simple accuracy boost for core excitation calculations
Relativistic corrections (RC) greatly improve the accuracy of costly quantum mechanical calculations (evGW0) for the CORE65 benchmark set of molecular core excitations. Credit: Aalto University

Core-level spectroscopy is an important experimental technique in physics, chemistry and materials science. Core level experiments are often accompanied by quantum mechanical calculations that aid the interpretation of the measured data. A promising recent development is to use GW Green's function formalism as the quantum mechanical method of choice, which offers several distinct advantages over the conventional density-functional theory (DFT) choice.

CEST researchers have derived a relativistic correction scheme that improves the accuracy of 1s core-level binding energies calculated from Green's function theory in the GW approximation.

The scheme is element-specific and does not add computational overhead. It reduces the mean absolute error (MAE) of previously reported benchmark set of 65 core-state excitations from 0.55 eV to 0.30 eV, and eliminates the species dependence of the MAE, which otherwise increases with the atomic number.

The correction terms are available in the corresponding publication, and can now be widely deployed in molecular and materials science.

More information:
Levi Keller et al. Relativistic correction scheme for core-level binding energies from GW, The Journal of Chemical Physics (2020). DOI: 10.1063/5.0018231

Provided by Aalto University

Citation: Simple accuracy boost for core excitation calculations (2020, October 19) retrieved 15 September 2025 from https://sciencex.com/wire-news/364555661/simple-accuracy-boost-for-core-excitation-calculations.html
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