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arXiv · 1912.09553

Propagative Block Diagonalisation Diabatisation of DFT/MRCI Electronic States

Simon P. Neville·Issaka Seidu·Michael S. Schuurman
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Abstract

We present a framework for the calculation of diabatic states using the combined density functional theory and multireference configuration interaction (DFT/MRCI) method. Due to restrictions present in the current formulation of the DFT/MRCI method (a lack of analytical derivative couplings and the inability to use non-canonical Kohn-Sham orbitals), most common diabatisation strategies are not applicable. We demonstrate, however, that diabatic wavefunctions and potentials can be calculated at the DFT/MRCI level of theory using a propagative variant of the block diagonalisation diabatisation method (P-BDD). The proposed procedure is validated {\it via} the calculation of diabatic potentials for LiH and the simulation of the vibronic spectrum of pyrazine. In both cases, the combination of the DFT/MRCI and P-BDD methods is found to correctly recover the non-adiabatic coupling effects of the problem.

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Simon P. Neville, Issaka Seidu, Michael S. Schuurman. 2019-12-19. Propagative Block Diagonalisation Diabatisation of DFT/MRCI Electronic States. https://arxiv.org/abs/1912.09553

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