Scaled density functional theory correlation functionals

Mohammed M. Ghouri, Saurabh Singh, B. Ramachandran

Research output: Contribution to journalArticle

Abstract

We show that a simple one-parameter scaling of the dynamical correlation energy estimated by the density functional theory (DFT) correlation functionals helps increase the overall accuracy for several local and nonlocal functionals. The approach taken here has been described as the "scaled dynamical correlation" (SDC) method [Ramachandran, J. Phys. Chem. A 2006, 110, 396], and its justification is the same as that of the scaled external correlation (SEC) method of Brown and Truhlar. We examine five local and five nonlocal (hybrid) DFT functionals, the latter group including three functionals developed specifically for kinetics by the Truhlar group. The optimum scale factors are obtained by use of a set of 98 data values consisting of molecules, ions, and transition states. The optimum scale factors, found with a linear regression relationship, are found to differ from unity with a high degree of correlation in nearly every case, indicating that the deviation of calculated results from the experimental values are systematic and proportional to the dynamic correlation energy. As a consequence, the SDC scaling of dynamical correlation decreases the mean errors (signed and unsigned) by significant amounts in an overwhelming majority of cases. These results indicate that there are gains to be realized from further parametrization of several popular exchange-correlation functionals.

Original languageEnglish
Pages (from-to)10390-10399
Number of pages10
JournalJournal of Physical Chemistry A
Volume111
Issue number41
DOIs
Publication statusPublished - 18 Oct 2007
Externally publishedYes

Fingerprint

Correlation methods
functionals
Density functional theory
density functional theory
Linear regression
Linear Models
Ions
Molecules
Kinetics
scaling
regression analysis
unity
deviation
Datasets
energy
kinetics

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Scaled density functional theory correlation functionals. / Ghouri, Mohammed M.; Singh, Saurabh; Ramachandran, B.

In: Journal of Physical Chemistry A, Vol. 111, No. 41, 18.10.2007, p. 10390-10399.

Research output: Contribution to journalArticle

Ghouri, Mohammed M. ; Singh, Saurabh ; Ramachandran, B. / Scaled density functional theory correlation functionals. In: Journal of Physical Chemistry A. 2007 ; Vol. 111, No. 41. pp. 10390-10399.
@article{0a6123fae3594199a1b1681ede7a2f0f,
title = "Scaled density functional theory correlation functionals",
abstract = "We show that a simple one-parameter scaling of the dynamical correlation energy estimated by the density functional theory (DFT) correlation functionals helps increase the overall accuracy for several local and nonlocal functionals. The approach taken here has been described as the {"}scaled dynamical correlation{"} (SDC) method [Ramachandran, J. Phys. Chem. A 2006, 110, 396], and its justification is the same as that of the scaled external correlation (SEC) method of Brown and Truhlar. We examine five local and five nonlocal (hybrid) DFT functionals, the latter group including three functionals developed specifically for kinetics by the Truhlar group. The optimum scale factors are obtained by use of a set of 98 data values consisting of molecules, ions, and transition states. The optimum scale factors, found with a linear regression relationship, are found to differ from unity with a high degree of correlation in nearly every case, indicating that the deviation of calculated results from the experimental values are systematic and proportional to the dynamic correlation energy. As a consequence, the SDC scaling of dynamical correlation decreases the mean errors (signed and unsigned) by significant amounts in an overwhelming majority of cases. These results indicate that there are gains to be realized from further parametrization of several popular exchange-correlation functionals.",
author = "Ghouri, {Mohammed M.} and Saurabh Singh and B. Ramachandran",
year = "2007",
month = "10",
day = "18",
doi = "10.1021/jp0728353",
language = "English",
volume = "111",
pages = "10390--10399",
journal = "Journal of Physical Chemistry A",
issn = "1089-5639",
publisher = "American Chemical Society",
number = "41",

}

TY - JOUR

T1 - Scaled density functional theory correlation functionals

AU - Ghouri, Mohammed M.

AU - Singh, Saurabh

AU - Ramachandran, B.

PY - 2007/10/18

Y1 - 2007/10/18

N2 - We show that a simple one-parameter scaling of the dynamical correlation energy estimated by the density functional theory (DFT) correlation functionals helps increase the overall accuracy for several local and nonlocal functionals. The approach taken here has been described as the "scaled dynamical correlation" (SDC) method [Ramachandran, J. Phys. Chem. A 2006, 110, 396], and its justification is the same as that of the scaled external correlation (SEC) method of Brown and Truhlar. We examine five local and five nonlocal (hybrid) DFT functionals, the latter group including three functionals developed specifically for kinetics by the Truhlar group. The optimum scale factors are obtained by use of a set of 98 data values consisting of molecules, ions, and transition states. The optimum scale factors, found with a linear regression relationship, are found to differ from unity with a high degree of correlation in nearly every case, indicating that the deviation of calculated results from the experimental values are systematic and proportional to the dynamic correlation energy. As a consequence, the SDC scaling of dynamical correlation decreases the mean errors (signed and unsigned) by significant amounts in an overwhelming majority of cases. These results indicate that there are gains to be realized from further parametrization of several popular exchange-correlation functionals.

AB - We show that a simple one-parameter scaling of the dynamical correlation energy estimated by the density functional theory (DFT) correlation functionals helps increase the overall accuracy for several local and nonlocal functionals. The approach taken here has been described as the "scaled dynamical correlation" (SDC) method [Ramachandran, J. Phys. Chem. A 2006, 110, 396], and its justification is the same as that of the scaled external correlation (SEC) method of Brown and Truhlar. We examine five local and five nonlocal (hybrid) DFT functionals, the latter group including three functionals developed specifically for kinetics by the Truhlar group. The optimum scale factors are obtained by use of a set of 98 data values consisting of molecules, ions, and transition states. The optimum scale factors, found with a linear regression relationship, are found to differ from unity with a high degree of correlation in nearly every case, indicating that the deviation of calculated results from the experimental values are systematic and proportional to the dynamic correlation energy. As a consequence, the SDC scaling of dynamical correlation decreases the mean errors (signed and unsigned) by significant amounts in an overwhelming majority of cases. These results indicate that there are gains to be realized from further parametrization of several popular exchange-correlation functionals.

UR - http://www.scopus.com/inward/record.url?scp=35948955575&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=35948955575&partnerID=8YFLogxK

U2 - 10.1021/jp0728353

DO - 10.1021/jp0728353

M3 - Article

VL - 111

SP - 10390

EP - 10399

JO - Journal of Physical Chemistry A

JF - Journal of Physical Chemistry A

SN - 1089-5639

IS - 41

ER -