Unitary coupled-cluster approach for the calculation of core-excited states and x-ray absorption spectra

In this work, we present the core-valence separation (CVS) approximation applied to unitary coupled-cluster (UCC) theory for the calculation of core-excited states and the simulation of x-ray absorption spectroscopy (XAS). Excitation energies and oscillator strengths of small- to medium-sized organi...

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Main Authors: Thielen, Sebastian M. (Author) , Hodecker, Manuel (Author) , Piazolo, Julia (Author) , Rehn, Dirk R. (Author) , Dreuw, Andreas (Author)
Format: Article (Journal)
Language:English
Published: 20 April 2021
In: The journal of chemical physics
Year: 2021, Volume: 154, Issue: 15, Pages: 1-8
ISSN:1089-7690
DOI:10.1063/5.0047134
Online Access:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1063/5.0047134
Verlag, lizenzpflichtig, Volltext: https://aip.scitation.org/doi/10.1063/5.0047134
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Author Notes:Sebastian M. Thielen, Manuel Hodecker, Julia Piazolo, Dirk R. Rehn, and Andreas Dreuw
Description
Summary:In this work, we present the core-valence separation (CVS) approximation applied to unitary coupled-cluster (UCC) theory for the calculation of core-excited states and the simulation of x-ray absorption spectroscopy (XAS). Excitation energies and oscillator strengths of small- to medium-sized organic molecules have been computed using the second-order and extended second-order UCC schemes (CVS-UCC2 and CVS-UCC2-x) as well as the third-order scheme (CVS-UCC3). All results are compared to the corresponding algebraic-diagrammatic construction methods and experimental data. The agreement between CVS-UCC and experimental data demonstrates its potential as a new approach for the calculation of XAS.
Item Description:Gesehen am 20.05.2021
Physical Description:Online Resource
ISSN:1089-7690
DOI:10.1063/5.0047134