Accuracy assessment of the ROHF-CCSD(T) calculations of static dipole polarizabilities of diatomic radicals: O-2, CN, and NO

Citation
M. Medved et al., Accuracy assessment of the ROHF-CCSD(T) calculations of static dipole polarizabilities of diatomic radicals: O-2, CN, and NO, J MOL ST-TH, 547, 2001, pp. 219-232
Citations number
93
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM
ISSN journal
0166-1280 → ACNP
Volume
547
Year of publication
2001
Pages
219 - 232
Database
ISI
SICI code
0166-1280(20010723)547:<219:AAOTRC>2.0.ZU;2-Z
Abstract
Static dipole polarizabilities of three radicals, O-2, CN, and NO were calc ulated by the coupled cluster CCSD(T) method, with the single determinant r estricted open shell Hartree-Fock (ROHF) reference using the finite field m ethod. O-2 and CN are generally considered as difficult systems sensitive t o spin contamination. The effect of spin adaptation in the CCSD(T) method w ith the ROHF reference was considered. Largest single and double excitation amplitudes and the T-1 diagnostics were used as indicators in the quality assessment of calculated dipole polarizabilities. We also discuss these mea sures in relation to similar quantities for selected closed shell systems f or which benchmark results are available. The size and quality of the basis set were systematically improved. Theoretical dipole polarizabilities were corrected for vibration effects and compared with available experimental v alues. (C) 2001 Elsevier Science B.V. All rights reserved.