Potential energy surfaces of LaH sup + and LaH sup + sub 2

Journal Article · Fri Mar 01 04:00:00 EST 1991 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.459743· OSTI ID:6190033

Das, K K; Balasubramanian, K ^[1]

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

Using the complete active space multiconfiguration self-consistent field (CAS-MCSCF) followed by full second-order configuration interaction (SOCI) calculations, 16 electronic states of LaH{sup +} and 8 electronic states of LaH{sup +}{sub 2} are investigated. The potential energy surface of these electronic states of LaH{sup +}{sub 2} and LaH{sup +} are computed. These calculations show that the {sup 3}{ital F}(5{ital d}{sup 2}) ground state of La{sup +} ion forms a weak complex with H{sub 2}. The La{sup +}({sup 1}{ital D}) excited state inserts into H{sub 2} with a small barrier ({lt}8 kcal/mol) to form the {sup 1}{ital A}{sub 1} ground state of LaH{sup +}{sub 2} ({ital r}{sub {ital e}}=2.057 A, {theta}{sub {ital e}}=106{degree}). At the SOCI level of theory LaH{sup +}{sub 2} is found to be 11 kcal/mol more stable than La{sup +}({sup 3}{ital F})+H{sub 2}. Our calculations explain the experimental observations on La{sup +}+H{sub 2}{r arrow}LaH{sup +}+H reaction. The adiabatic ionization potential (IP) of LaH{sub 2} and LaH are calculated as 5.23 and 5.33 eV, respectively. The ground state of LaH{sup +} was found to be a {sup 2}{Delta} state. We compute {ital D}{sub {ital e}}(LaH{sup +}) and {ital D}{sub {ital e}}(HLa--H{sup +}) as 2.54 eV in excellent agreement with the experimental {ital D}{sub {ital e}}(LaH{sup +})=2.57 eV measured by Armentrout and co-workers. The spin--orbit effects of LaH{sup +} were also studied using the relativistic configuration interaction (RCI) method.

• DOE Contract Number: FG02-86ER13558
• OSTI ID: 6190033
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 94:5; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CATIONS
CHARGED PARTICLES
CONFIGURATION INTERACTION
CORRECTIONS
COUPLING
DISSOCIATION ENERGY
ELECTRONIC STRUCTURE
ENERGY
ENERGY LEVELS
GROUND STATES
HYDRIDES
HYDROGEN COMPOUNDS
INTERMEDIATE COUPLING
IONS
L-S COUPLING
LANTHANUM COMPOUNDS
LANTHANUM HYDRIDES
MOLECULAR IONS
POTENTIAL ENERGY
RADIATIVE CORRECTIONS
RARE EARTH COMPOUNDS