Novel Approach to Structural Relaxation of Materials in Optically Excited States

Mao Yang; Claudia Draxl

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arXiv · 2212.13645

Novel Approach to Structural Relaxation of Materials in Optically Excited States

Mao Yang·Claudia Draxl

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Abstract

We present a first-principles method for relaxing a material's geometry in an optically excited state. This method, based on the Bethe-Salpeter equation, consists of solving coupled equations for exciton wavefunctions and atomic displacements. Our approach allows for structural relaxation of excited states to be achieved through a single iteration. As results, one obtains not only energy and wavefunction of the thus modified, i.e. self-trapped, exciton, but also the mechanism of relaxation in terms of atomic displacements in the respective phonon eigenmodes. We demonstrate and evaluate our formalism with the example of the three molecules CO, H$_{2}$O, and NH$_{3}$.

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Mao Yang, Claudia Draxl. 2022-12-27. Novel Approach to Structural Relaxation of Materials in Optically Excited States. https://arxiv.org/abs/2212.13645

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