The Journal of Chemical Physics [LCQ]

Abstract

The equivalence in one-electron quantum baths between the practical implementation of density matrix embedding theory (DMET) and the more recent Householder-transformed density matrix functional embedding theory has been shown previously in the standard but special case where the reference full-size (one-electron reduced) density matrix, from which the bath is constructed, is idempotent [S. Yalouz et al., J. Chem. Phys. 157, 214112 (2022)]. We prove mathematically that the equivalence remains valid when the density matrix is not idempotent anymore, thus allowing for the construction of correlated (one-electron) quantum baths. A density-matrix functional exactification of DMET is derived within the present unified quantum embedding formalism. Numerical examples reveal that the embedding cluster can be quite sensitive to the level of density-matrix functional approximation used for computing the reference density matrix.

 

Reference

A unified density matrix functional construction of quantum baths in density matrix embedding theory beyond the mean-field approximation

Sajanthan Sekaran, Oussama Bindech, and Emmanuel Fromager

J. Chem. Phys. 159, 034107 (2023) – DOI : https://doi.org/10.1063/5.0157746

 

Contact

Emmanuel FROMAGER (team LCQ), Institut de Chimie de Strasbourg (UMR 7177).