Academic Journal

Direct minimization of Hartree-Fock-Roothaan energy functionals using derivative-free optimization algorithms: a case study on the use of noninteger Slater-type orbitals.

Bibliographic Details
Title: Direct minimization of Hartree-Fock-Roothaan energy functionals using derivative-free optimization algorithms: a case study on the use of noninteger Slater-type orbitals.
Authors: BAĞCI, Ali1 abagci@pau.edu.tr
Source: Turkish Journal of Physics. 2026, Vol. 50 Issue 3, p148-169. 22p.
Subject Terms: *Simplex algorithm, *Atomic models, *Heuristic, *Radial basis functions, *Nonsmooth optimization
Abstract: This study presents an evaluation of derivative-free optimization algorithms for the direct minimization of Hartree-Fock-Roothaan energy functionals involving nonlinear orbital parameters and noninteger-order quantum numbers. The analysis focuses on atomic calculations employing noninteger Slater-type orbitals. Analytic derivatives of the energy functional are not readily available for these orbitals. Four methods are investigated under identical numerical conditions: Powell's conjugate-direction method, the Nelder-Mead simplex algorithm, coordinate-based pattern search, and a model-based algorithm utilizing radial basis functions for surrogate-model construction. Performance analysis is first carried out using the Powell singular function, a well-established test case exhibiting challenging properties, including Hessian singularity at the global minimum. The algorithms are then applied to Hartree-Fock-Roothaan self-consistent-field energy functionals, which define a highly nonconvex optimization landscape due to the nonlinear coupling of orbital parameters. Illustrative examples are provided for closed-shell atomic configurations, specifically the He and Be isoelectronic series, with calculations performed for energy functionals involving up to eight nonlinear parameters. This work presents the first systematic investigation of derivative-free optimization methods for Hartree-Fock-Roothaan energy minimization with noninteger Slater orbitals. [ABSTRACT FROM AUTHOR]
Database: Academic Search Index
FullText Text:
  Availability: 0
CustomLinks:
  – Url: https://resolver.ebsco.com/c/fiv2js/result?sid=EBSCO:asx&genre=article&issn=13000101&ISBN=&volume=50&issue=3&date=20260501&spage=148&pages=148-169&title=Turkish Journal of Physics&atitle=Direct%20minimization%20of%20Hartree-Fock-Roothaan%20energy%20functionals%20using%20derivative-free%20optimization%20algorithms%3A%20a%20case%20study%20on%20the%20use%20of%20noninteger%20Slater-type%20orbitals.&aulast=BA%C4%9ECI%2C%20Ali&id=DOI:10.55730/1300-0101.2810
    Name: Full Text Finder (for New FTF UI) (ns324271)
    Category: fullText
    Text: Full Text Finder
    MouseOverText: Full Text Finder
Header DbId: asx
DbLabel: Academic Search Index
An: 194891115
RelevancyScore: 1431
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 1430.76245117188
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Direct minimization of Hartree-Fock-Roothaan energy functionals using derivative-free optimization algorithms: a case study on the use of noninteger Slater-type orbitals.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22BAĞCI%2C+Ali%22">BAĞCI, Ali</searchLink><relatesTo>1</relatesTo><i> abagci@pau.edu.tr</i>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Turkish+Journal+of+Physics%22">Turkish Journal of Physics</searchLink>. 2026, Vol. 50 Issue 3, p148-169. 22p.
– Name: Subject
  Label: Subject Terms
  Group: Su
  Data: *<searchLink fieldCode="DE" term="%22Simplex+algorithm%22">Simplex algorithm</searchLink><br />*<searchLink fieldCode="DE" term="%22Atomic+models%22">Atomic models</searchLink><br />*<searchLink fieldCode="DE" term="%22Heuristic%22">Heuristic</searchLink><br />*<searchLink fieldCode="DE" term="%22Radial+basis+functions%22">Radial basis functions</searchLink><br />*<searchLink fieldCode="DE" term="%22Nonsmooth+optimization%22">Nonsmooth optimization</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: This study presents an evaluation of derivative-free optimization algorithms for the direct minimization of Hartree-Fock-Roothaan energy functionals involving nonlinear orbital parameters and noninteger-order quantum numbers. The analysis focuses on atomic calculations employing noninteger Slater-type orbitals. Analytic derivatives of the energy functional are not readily available for these orbitals. Four methods are investigated under identical numerical conditions: Powell's conjugate-direction method, the Nelder-Mead simplex algorithm, coordinate-based pattern search, and a model-based algorithm utilizing radial basis functions for surrogate-model construction. Performance analysis is first carried out using the Powell singular function, a well-established test case exhibiting challenging properties, including Hessian singularity at the global minimum. The algorithms are then applied to Hartree-Fock-Roothaan self-consistent-field energy functionals, which define a highly nonconvex optimization landscape due to the nonlinear coupling of orbital parameters. Illustrative examples are provided for closed-shell atomic configurations, specifically the He and Be isoelectronic series, with calculations performed for energy functionals involving up to eight nonlinear parameters. This work presents the first systematic investigation of derivative-free optimization methods for Hartree-Fock-Roothaan energy minimization with noninteger Slater orbitals. [ABSTRACT FROM AUTHOR]
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=asx&AN=194891115
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.55730/1300-0101.2810
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 22
        StartPage: 148
    Subjects:
      – SubjectFull: Simplex algorithm
        Type: general
      – SubjectFull: Atomic models
        Type: general
      – SubjectFull: Heuristic
        Type: general
      – SubjectFull: Radial basis functions
        Type: general
      – SubjectFull: Nonsmooth optimization
        Type: general
    Titles:
      – TitleFull: Direct minimization of Hartree-Fock-Roothaan energy functionals using derivative-free optimization algorithms: a case study on the use of noninteger Slater-type orbitals.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: BAĞCI, Ali
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 05
              Text: 2026
              Type: published
              Y: 2026
          Identifiers:
            – Type: issn-print
              Value: 13000101
          Numbering:
            – Type: volume
              Value: 50
            – Type: issue
              Value: 3
          Titles:
            – TitleFull: Turkish Journal of Physics
              Type: main
ResultId 1