Third-order density-functional perturbation theory: a practical implementation with applications to anharmonic couplings in Si

Alberto Debernardi; Stefano Baroni

doi:10.1016/0038-1098(94)90654-8

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Third-order density-functional perturbation theory: a practical implementation with applications to anharmonic couplings in Si

Alberto Debernardi·Stefano Baroni

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Abstract

We present a formulation of third-order density-functional perturbation theory which is manifestly invariant with respect to unitary transfomations within the occupied-states manifold and is particularly suitable for a practical implementation of the so called `2n+1' theorem. Our implementation is demonstrated with the calculation of the third-order anharmonic coupling coefficients for some high-simmetry phonons in Silicon.

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Alberto Debernardi, Stefano Baroni. 1994-06-15. Third-order density-functional perturbation theory: a practical implementation with applications to anharmonic couplings in Si. https://doi.org/10.1016/0038-1098(94)90654-8

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