Benchmark of Excitation Energy Shifts from Frozen-Density Embedding Theory: Introduction of a Density-Overlap-Based Applicability Threshold

Alexander Zech; Niccolò Ricardi; Stefan Prager; Andreas Dreuw; Tomasz A Wesolowski

doi:10.1021/acs.jctc.8b00201

Benchmark of Excitation Energy Shifts from Frozen-Density Embedding Theory: Introduction of a Density-Overlap-Based Applicability Threshold

J Chem Theory Comput. 2018 Aug 14;14(8):4028-4040. doi: 10.1021/acs.jctc.8b00201. Epub 2018 Jul 2.

Authors

Alexander Zech¹, Niccolò Ricardi¹, Stefan Prager², Andreas Dreuw², Tomasz A Wesolowski¹

Affiliations

¹ Department of Physical Chemistry , University of Geneva , Geneva , Switzerland.
² Interdisciplinary Center for Scientific Computing , University of Heidelberg , Heidelberg , Germany.

PMID: 29906111
DOI: 10.1021/acs.jctc.8b00201

Abstract

We present a thorough investigation of the errors in results obtained with the combination of frozen-density embedding theory and the algebraic diagrammatic construction scheme for the polarization propagator of second order (FDE-ADC(2)). The study was carried out on a set of 52 intermolecular complexes with varying interaction strength, each consisting of a chromophore of fundamental interest and a few small molecules in its environment. The errors emerging in frozen-density embedding theory-based methods originate from (a) the solver of the quantum many-body problem used to obtain the embedded wave function (Ψ_A^emb), (b) the approximation for the explicit density functional for the embedding potential, and (c) the choice of the density representing the environment (ρ_B( r⃗)). The present work provides a comprehensive analysis of the errors in the excitation energies based on the last two factors. Furthermore, a density-overlap-based parameter is proposed to be used as an a priori criterion of applicability.