IQA Analysis of the Two-Particle Density Matrix: Chemical Insight and Computational Efficiency

Mark Vincent; Paul Popelier

IQA Analysis of the Two-Particle Density Matrix: Chemical Insight and Computational Efficiency

Mark Vincent, Paul Popelier

Computational and Theoretical Chemistry

Research output: Contribution to journal › Article › peer-review

9 Downloads (Pure)

Abstract

The Interacting Quantum Atoms (IQA) method offers a rigorous and minimal route to calculate atomic electron correlation energies from the two-particle density matrix (2PDM). The price paid is that this method is very time-consuming. However, employing CCSD and CCSD(T), we explore several approaches to speed up such calculations. We make the pivotal observation that the removal, from the true 2PDM, of both the Hartree-Fock part of the 2PDM, and an approximate 2PDM (Müller) dramatically reduces the size of the quadrature grid needed to obtain accurate energies.

Original language	English
Journal	Theoretical Chemistry Accounts
Publication status	Accepted/In press - 27 Sept 2023

Keywords

Quantum Chemical Topology (QCT
Interacting Quantum Atoms (IQA)
QTAIM
Electron Correlation
CCSD(T)

Access to Document

CCSD(T) IQA ms resubmitAccepted author manuscript, 167 KBLicence: CC BY

Cite this

@article{2b23a9574eed4905825dd48c78786154,

title = "IQA Analysis of the Two-Particle Density Matrix: Chemical Insight and Computational Efficiency",

abstract = "The Interacting Quantum Atoms (IQA) method offers a rigorous and minimal route to calculate atomic electron correlation energies from the two-particle density matrix (2PDM). The price paid is that this method is very time-consuming. However, employing CCSD and CCSD(T), we explore several approaches to speed up such calculations. We make the pivotal observation that the removal, from the true 2PDM, of both the Hartree-Fock part of the 2PDM, and an approximate 2PDM (M{\"u}ller) dramatically reduces the size of the quadrature grid needed to obtain accurate energies. ",

keywords = "Quantum Chemical Topology (QCT, Interacting Quantum Atoms (IQA), QTAIM, Electron Correlation, CCSD(T)",

author = "Mark Vincent and Paul Popelier",

year = "2023",

month = sep,

day = "27",

language = "English",

journal = "Theoretical Chemistry Accounts",

issn = "1432-881X",

publisher = "Springer New York",

}

TY - JOUR

T1 - IQA Analysis of the Two-Particle Density Matrix: Chemical Insight and Computational Efficiency

AU - Vincent, Mark

AU - Popelier, Paul

PY - 2023/9/27

Y1 - 2023/9/27

N2 - The Interacting Quantum Atoms (IQA) method offers a rigorous and minimal route to calculate atomic electron correlation energies from the two-particle density matrix (2PDM). The price paid is that this method is very time-consuming. However, employing CCSD and CCSD(T), we explore several approaches to speed up such calculations. We make the pivotal observation that the removal, from the true 2PDM, of both the Hartree-Fock part of the 2PDM, and an approximate 2PDM (Müller) dramatically reduces the size of the quadrature grid needed to obtain accurate energies.

AB - The Interacting Quantum Atoms (IQA) method offers a rigorous and minimal route to calculate atomic electron correlation energies from the two-particle density matrix (2PDM). The price paid is that this method is very time-consuming. However, employing CCSD and CCSD(T), we explore several approaches to speed up such calculations. We make the pivotal observation that the removal, from the true 2PDM, of both the Hartree-Fock part of the 2PDM, and an approximate 2PDM (Müller) dramatically reduces the size of the quadrature grid needed to obtain accurate energies.

KW - Quantum Chemical Topology (QCT

KW - Interacting Quantum Atoms (IQA)

KW - QTAIM

KW - Electron Correlation

KW - CCSD(T)

M3 - Article

SN - 1432-881X

JO - Theoretical Chemistry Accounts

JF - Theoretical Chemistry Accounts

ER -

IQA Analysis of the Two-Particle Density Matrix: Chemical Insight and Computational Efficiency

Abstract

Keywords

Access to Document

Fingerprint

Cite this