Potential energy surfaces for NbH sup + sub 2 and MoH sup + sub 2

Journal Article · Wed Nov 15 04:00:00 EST 1989 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.457392· OSTI ID:5368292

Das, K K; Balasubramanian, K ^[1]

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1. Department of Chemistry, Arizona State University, Tempe, Arizona 85287-1604 (US)

Electronic structures, potential energy surfaces (PES), and some one-electron properties of 12 electronic states of the NbH{sup +}{sub 2} and MoH{sup +}{sub 2} ions are studied using the complete active space MCSCF (CASSCF) followed by multireference singles plus doubles configuration interaction (MRSDCI) calculations. The {sup 3}{ital B}{sub 2} ground state of NbH{sup +}{sub 2} ({ital r}{sub {ital e}} =1.687 A, {theta}{sub {ital e}} =105.2{degree}) is formed by the spontaneous insertion of Nb{sup +}({ital a}{sup 3}{ital F}, 4{ital d}{sup 3}5{ital s}{sup 1}) into H{sub 2} while the lowest {ital a} {sup 5}{ital F}(4{ital d}{sup 3}5{ital s}{sup 1}) state of the Nb{sup +} ion has to surmount a barrier to 56 kcal/mol to insert into H{sub 2}. The ground state ({sup 4}{ital B}{sub 2}) potential energy curve of MoH{sup +}{sub 2} contains two minima with geometries: {ital r}{sub {ital e}} =1.637 A, {theta}{sub {ital e}} =37{degree} and {ital r}{sub {ital e}} =1.626 A, {theta}{sub {ital e}} =115.7{degree}. The {ital a}{sup 4}{ital G} state of Mo{sup +} inserts spontaneously into H{sub 2} to form the {sup 4}{ital B}{sub 2} state of MoH{sup +}{sub 2}, while the ground state ({ital a} {sup 6}{ital S}, 4{ital d}{sup 5}) of the Mo{sup +} ion has to overcome a barrier of 74 kcal/mol to form the linear {sup 6}{Pi}{sub {ital u}} state of the MoH{sup +}{sub 2} ion. In the collinear mode of interaction, the ground state of Mo{sup +} forms a van der Waals complex which is only 1.2 kcal/mol more stable than Mo{sup +}+H{sub 2}. In general, all the low-lying states of NbH{sup +}{sub 2} and MoH{sup +}{sub 2} are formed from the excited low-spin states of the metal ions. The PES of NbH{sup +}{sub 2} were found to be similar to the neutral surfaces confirming Smalley and coworkers experimental findings. The addition of {ital f}-type diffuse functions does not alter the geometries much.

• OSTI ID: 5368292
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 91:10; 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
CHEMICAL REACTIONS
CONFIGURATION INTERACTION
ELECTRONIC STRUCTURE
HYDRIDES
HYDROGEN COMPOUNDS
IONIZATION POTENTIAL
IONS
MOLYBDENUM COMPOUNDS
MOLYBDENUM HYDRIDES
NIOBIUM COMPOUNDS
NIOBIUM HYDRIDES
REACTIVITY
REFRACTORY METAL COMPOUNDS
TRANSITION ELEMENT COMPOUNDS