z-logo
Premium
A fast approximate extension of the interacting quantum atoms energy decomposition to excited states
Author(s) -
JaraCortés Jesús,
Matta Chérif F.,
HernándezTrujillo Jesús
Publication year - 2022
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.26863
Subject(s) - excited state , density matrix , quantum , density functional theory , pairwise comparison , matrix (chemical analysis) , chemistry , atomic physics , electronic structure , quantum mechanics , statistical physics , physics , mathematics , statistics , chromatography
An approach is developed for the fast calculation of the interacting quantum atoms energy decomposition (IQA) from the information contained in the first order reduced density matrix only. The proposed methodology utilizes an approximate exchange‐correlation density from Density Matrix Functional Theory without the need to evaluate the correlation‐exchange contribution directly. Instead, weight factors are estimated to decompose the exact V xc into atomic and pairwise contributions. In this way, the sum of the IQA contributions recovers the energy obtained from the electronic structure calculation. This method can, hence, be applied to obtain atomic contributions in excited states on the same footing as in their ground states using any method that delivers the reduced first‐order density matrix. In this way, one can locate chromophores from first principles quantum chemical calculations. Test calculations on the ground and excited states of a set of small molecules indicate that the scaled atomic contributions reproduce vertical electronic transition energies calculated exactly. This approach may be useful to extend the applicability of the IQA approach in the study of large photochemical systems especially when the calculations of the second order reduced density matrices is prohibitive or not possible.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here