1 Ocak 2020 Dergi makalesi Açık Erişim

Warden, Constance E.; Smith, Daniel G. A.; Burns, Lori A.; Bozkaya, Ugur; Sherrill, C. David

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{
  "@context": "https://schema.org/", 
  "@id": 5751, 
  "@type": "ScholarlyArticle", 
  "creator": [
    {
      "@type": "Person", 
      "name": "Warden, Constance E."
    }, 
    {
      "@type": "Person", 
      "name": "Smith, Daniel G. A."
    }, 
    {
      "@type": "Person", 
      "name": "Burns, Lori A."
    }, 
    {
      "@type": "Person", 
      "affiliation": "Hacettepe Univ, Dept Chem, TR-06800 Ankara, Turkey", 
      "name": "Bozkaya, Ugur"
    }, 
    {
      "@type": "Person", 
      "name": "Sherrill, C. David"
    }
  ], 
  "datePublished": "2020-01-01", 
  "description": "The focal-point approach, combining several quantum chemistry computations to estimate a more accurate computation at a lower expense, is effective and commonly used for energies. However, it has not yet been widely adopted for properties such as geometries. Here, we examine several focal-point methods combining MOller-Plesset perturbation theory (MP2 and MP2.5) with coupled-cluster theory through perturbative triples [CCSD(T)] for their effectiveness in geometry optimizations using a new driver for the Psi4 electronic structure program that efficiently automates the computation of composite-energy gradients. The test set consists of 94 closed-shell molecules containing first- and/or second-row elements. The focal-point methods utilized combinations of correlation-consistent basis sets cc-pV(X+d)Z and heavy-aug-cc-pV(X+d)Z (X = D, T, Q, 5, 6). Focal-point geometries were compared to those from conventional CCSD(T) using basis sets up to heavy-aug-cc-pV5Z and to geometries from explicitly correlated CCSD(T)-F12 using the cc-pVXZ-F12 (X = D, T) basis sets. All results were compared to reference geometries reported by Karton et al. [J. Chem. Phys. 145, 104101 (2016)] at the CCSD(T)/heavy-aug-cc-pV6Z level of theory. In general, focal-point methods based on an estimate of the MP2 complete-basis-set limit, with a coupled-cluster correction evaluated in a (heavy-aug-)cc-pVXZ basis, are of superior quality to conventional CCSD(T)/(heavy-aug-)cc-pV(X+1)Z and sometimes approach the errors of CCSD(T)/(heavy-aug-)cc-pV(X+2)Z. However, the focal-point methods are much faster computationally. For the benzene molecule, the gradient of such a focal-point approach requires only 4.5% of the computation time of a conventional CCSD(T)/cc-pVTZ gradient and only 0.4% of the time of a CCSD(T)/cc-pVQZ gradient.", 
  "headline": "Efficient and automated computation of accurate molecular geometries using focal-point approximations to large-basis coupled-cluster theory", 
  "identifier": 5751, 
  "image": "https://aperta.ulakbim.gov.tr/static/img/logo/aperta_logo_with_icon.svg", 
  "license": "http://www.opendefinition.org/licenses/cc-by", 
  "name": "Efficient and automated computation of accurate molecular geometries using focal-point approximations to large-basis coupled-cluster theory", 
  "url": "https://aperta.ulakbim.gov.tr/record/5751"
}