Benchmark calculations with correlated molecular wave functions. VI. Second row A[sub 2] and first row/second row AB diatomic molecules

Journal Article · Tue Nov 15 04:00:00 EST 1994 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.468080· OSTI ID:6836877

Woon, D E; Dunning, Jr, T H ^[1]

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1. Molecular Science Research Center, Pacific Northwest Laboratory, Richland, Washington 99352 (United States)

Benchmark calculations employing the correlation consistent basis sets of Dunning and co-workers are reported for the following diatomic species: Al[sub 2], Si[sub 2], P[sub 2], S[sub 2], Cl[sub 2], SiS, PS, PN, PO, and SO. Internally contracted multireference configuration interaction (CMRCI) calculations (correlating valence electrons only) have been performed for each species. For Cl[sub 2], P[sub 2], and PN, calculations have also been carried out using Moller--Plesset perturbation theory (MP2, MP3, MP4) and the singles and doubles coupled-cluster method with and without perturbative triples [CCSD, CCSD(T)]. Spectroscopic constants and dissociation energies are reported for the ground state of each species. In addition, the low-lying excited states of Al[sub 2] and Si[sub 2] have been investigated. Estimated complete basis set (CBS) limits for the dissociation energies, [ital D][sub [ital e]], and other spectroscopic constants are obtained from simple exponential extrapolations of the computed quantities. At the CBS limit the root-mean-square (rms) error in [ital D][sub [ital e]] for the CMRCI calculations, the intrinsic error, on the ten species considered here is 3.9 kcal/mol; for [ital r][sub [ital e]] the rms intrinsic error is 0.009 A, and for [omega][sub [ital e]] it is 5.1 cm[sup [minus]1].

• DOE Contract Number: AC06-76RL01830; FG06-89ER75522
• OSTI ID: 6836877
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 101:10; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664100* -- Theory of Electronic Structure of Atoms & Molecules-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ALUMINIUM
CHALCOGENIDES
CHLORINE
DISSOCIATION ENERGY
ELEMENTS
ENERGY
ENERGY LEVELS
EXCITED STATES
FUNCTIONS
GROUND STATES
HALOGENS
METALS
NITRIDES
NITROGEN COMPOUNDS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PERTURBATION THEORY
PHOSPHORUS
PHOSPHORUS COMPOUNDS
PHOSPHORUS NITRIDES
PHOSPHORUS OXIDES
PHOSPHORUS SULFIDES
PNICTIDES
SEMIMETALS
SILICON
SILICON COMPOUNDS
SILICON SULFIDES
SPECTROSCOPY
SULFIDES
SULFUR
SULFUR COMPOUNDS
SULFUR OXIDES
WAVE FUNCTIONS