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Updated: May 30, 2026
13:56
Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
Near-edge structures from first principles all-electron Bethe-Salpeter equation calculations
W Olovsson1, I Tanaka, P Puschnig
1Department of Materials Science and Engineering, Kyoto University, Sakyo, Kyoto 606-8501, Japan.
Summary
This study calculates X-ray absorption near-edge structures (XANES) using the Bethe-Salpeter equation (BSE) for lithium compounds. Results accurately predict excited states and core-exciton properties in these materials.
Area of Science:
- Solid-state physics
- Computational materials science
- Quantum chemistry
Background:
- X-ray absorption near-edge structures (XANES) provide insights into electronic structure.
- Accurate theoretical methods are needed to interpret XANES spectra.
- Previous methods often relied on approximations for electron-hole interactions.
Purpose of the Study:
- To calculate XANES spectra for Li K-edge in LiF, Li(2)O, and Li(2)S.
- To compare Bethe-Salpeter equation (BSE) results with independent particle approximations.
- To investigate the accuracy of the all-electron full-potential linearized augmented plane wave (FPLAPW) method for excited states.
Main Methods:
- Solving the Bethe-Salpeter equation (BSE) for the two-particle Green's function.
- Utilizing the all-electron full-potential linearized augmented plane wave (FPLAPW) method.
- Comparing BSE results with Random Phase Approximation (RPA) and Density Functional Theory (DFT) core-hole calculations.
Main Results:
- Accurate prediction of excited states for Li K-edge in LiF, Li(2)O, and Li(2)S.
- Determination of binding energies for strongly bound excitations.
- Demonstration of core-exciton wavefunctions, particularly for LiF.
Conclusions:
- The BSE approach within FPLAPW accurately describes XANES spectra.
- The method provides reliable binding energies and exciton properties.
- This work validates advanced theoretical methods for studying electronic excitations in solids.
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