Potential energy surfaces for the insertion of Ta and Ta sup + into H sub 2

Journal Article · Sun Dec 15 00:00:00 EST 1991 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.461188· OSTI ID:6154572

Dai, D G; Cheng, W; Balasubramanian, K ^[1]

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1. Department of Chemistry, Arizona State University, Tempe, Arizona (USA)

We compute the bending potential energy surfaces of 12 electronic states of TaH{sub 2} and TaH{sup +}{sub 2} using the complete active space multiconfiguration self-consistent field (CAS-MCSCF) followed by multireference singles+doubles configuration interaction (MRSDCI) calculations. Spin--orbit effects are also included using the relativistic configuration interaction (RCI) approach. We find that the {sup 4}{ital F} ground state of Ta atom requires a barrier of {similar to}24 kcal/mol for insertion into H{sub 2} while the {sup 5}{ital F} ground state of Ta{sup +} does not insert into H{sub 2}. The low-spin excited states of Ta and Ta{sup +} are considerably more reactive with H{sub 2}. We find three nearly-degenerate bent electronic states of {sup 4}{ital B}{sub 1}, {sup 4}{ital A}{sub 2}, and {sup 4}{ital B}{sub 2} symmetries as the candidates for the ground state of TaH{sub 2}. Likewise {sup 3}{ital B}{sub 1} and {sup 3}{ital A}{sub 1} electronic states of TaH{sup +}{sub 2} are nearly-degenerate candidates for the ground state. The spin--orbit coupling strongly mixes some of these states leading to bond angle changes of up to 10{degree}.

• DOE Contract Number: FG02-86ER13558
• OSTI ID: 6154572
• Journal Information: Journal of Chemical Physics; (United States), Vol. 95:12; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HYDROGEN
CHEMICAL REACTIONS
MOLECULAR IONS
POTENTIAL ENERGY
TANTALUM
TANTALUM HYDRIDES
TANTALUM IONS
BOND ANGLE
CATIONS
CONFIGURATION INTERACTION
EXCITED STATES
GROUND STATES
L-S COUPLING
MOLECULES
SPIN
SYMMETRY
ANGULAR MOMENTUM
CHARGED PARTICLES
COUPLING
ELEMENTS
ENERGY
ENERGY LEVELS
HYDRIDES
HYDROGEN COMPOUNDS
INTERMEDIATE COUPLING
IONS
METALS
NONMETALS
PARTICLE PROPERTIES
REFRACTORY METAL COMPOUNDS
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties