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Communication: Random phase approximation renormalized many-body perturbation theory.
Jefferson E Bates1, Filipp Furche
1Department of Chemistry, University of California, Irvine, 1102 Natural Sciences II, Irvine, California 92697-2025, USA.
The Journal of Chemical Physics
|November 12, 2013
Summary
We developed a new computational method, RPA-renormalized perturbation theory with an approximate exchange kernel (AXK), to accurately study electronic properties. This method improves calculations for challenging small-gap systems without high computational cost.
Area of Science:
- Computational Chemistry
- Quantum Mechanics
- Materials Science
Background:
- Many-body perturbation theory (MBPT) methods are crucial for electronic structure calculations.
- Standard methods like the random phase approximation (RPA) struggle with small-gap systems.
- Existing corrections can overcorrect or diverge for certain materials.
Purpose of the Study:
- To develop a robust and computationally efficient method for electronic structure calculations.
- To extend the applicability of MBPT to systems with small electronic band gaps.
- To improve the accuracy of theoretical predictions for material properties.
Main Methods:
- Derivation of a renormalized many-body perturbation theory (MBPT) starting from the random phase approximation (RPA).
- Introduction of the approximate exchange kernel (AXK) as the leading correction to RPA.
- Application of the RPA+AXK method to various chemical and material systems.
Main Results:
- The approximate exchange kernel (AXK) significantly improves RPA atomization energies and ionization potentials.
- RPA+AXK shows balanced performance, avoiding overcorrection issues seen in other methods.
- The method avoids the divergence of Møller-Plesset perturbation theory (MP2) for small-gap systems.
Conclusions:
- RPA+AXK offers an accurate, non-empirical, and robust alternative for electronic structure calculations.
- This method expands the range of systems accessible to first-principles calculations.
- RPA+AXK provides a valuable tool for assessing and improving semi-local density functional theory.
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