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Implementation of the Bethe-Salpeter equation in the TURBOMOLE program
Katharina Krause1, Wim Klopper1
1Karlsruhe Institute of Technology (KIT), Institute of Physical Chemistry, P.O. Box 6980, Karlsruhe, D-76049, Germany.
Journal of Computational Chemistry
|December 8, 2016
Summary
A TURBOMOLE software update enhances excited state calculations by solving the Bethe-Salpeter equation (BSE) using a resolution-of-the-identity (RI) approximation for improved accuracy in electronic structure theory.
Area of Science:
- Computational Chemistry
- Theoretical Chemistry
- Quantum Chemistry
Background:
- The Bethe-Salpeter equation (BSE) is crucial for accurately describing electronically excited states of atoms and molecules.
- Efficiently solving the BSE requires approximations for electron-repulsion integrals.
Discussion:
- This work introduces a software update for the ESCF module of the TURBOMOLE program, implementing a solution for the BSE.
- The update utilizes a resolution-of-the-identity (RI) approximation for two-electron electron-repulsion integrals.
- Symmetry, specifically for the D2h point group and its subgroups, is leveraged to optimize calculations.
Key Insights:
- The BSE approach is compatible with both spin-restricted and spin-unrestricted Kohn-Sham formalisms.
- Singlet and triplet excited states of closed-shell systems can be calculated using the spin-restricted formalism.
- The update also enables the RI approximation for Hartree-Fock exchange in time-dependent density-functional theory with hybrid functionals.
Outlook:
- This advancement facilitates more accurate theoretical descriptions of excited states in atomic and molecular systems.
- The integration of RI approximation with BSE and TD-DFT broadens the scope of accessible quantum chemical calculations.
Keywords:
Bethe−Salpeter equationelectronic excitation energyexchange interactionresolution-of-the-identity approximationtime-dependent density-functional theoryMore Related Videos
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