ISSN:
1572-8951
Schlagwort(e):
Density functional theory
;
molecular hyperpolarizabilities
;
relative accuracies
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract Recent density functional theory calculations of molecular hyperpolarizabilities are reviewed in order to try to assess the accuracy and reliability of DFT in the specified field by comparison with experiment and with ab initio HF and post-HF methods. In a table [1] (p. 157) containing results from the paper defining the compound electronic structure method Gaussian 2 [2], Foresman presents the relative accuracies of various 'model chemistries' for calculating thermochemical quantities. The Mean Absolute Deviation (MAD) from experiment, its Standard Deviation, and the largest positive and negative errors in the computed values, are the statistical means that allow the various models to be arranged in order of increasing MAD, and thus decreasing overall accuracy. These same statistical quantities, on a percent basis for size consistency and dimensionlessness, are used in this communication for quantifying the accuracies of various combinations of DFT functionals/basis sets/quantum chemical techniques/applied field strengths, in calculations of molecular mean dipole polarizabilities 〈α〉, first-order hyperpolarizabilities β∥ and second-order hyperpolarizabilities γ∥. The relative accuracies of DFT model chemistries are thus surveyed in three tables (including authors/references arranged in chronological order, compounds studied, and program codes employed), and can serve as guidelines for selecting optimal computational methodologies.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1008313115939
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