Potential energy surfaces for the Mo + H sub 2 reaction: Collinear versus perpendicular collisions

Journal Article · Thu Jan 25 00:00:00 EST 1990 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100365a013· OSTI ID:6654266

Li, Junqing; Balasubramanian, K ^[1]

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1. Arizona State Univ., Tempe (USA)

The potential energy surfaces (PES) of 16 electronic states for the Mo + H{sub 2} reaction are studied in two modes of collisions, namely collinear (C{sub {infinity}{nu}}) and perpendicular (C{sub 2{nu}}) modes, using the complete active space MCSCF (CASSCF) followed by multireference singles + doubles configuration interaction (MRSDCI) method. The effect of spin-orbit coupling on the ground state of MoH{sub 2} is also addressed by use of the relativistic CI (RCI) method. In the insertion mode (C{sub 2{nu}}), the {sup 7}S ground state of Mo has to surmount a barrier of 89 kcal/mol to insert with H{sub 2} to form the linear {sup 7}{Sigma}{sub g}{sup +} MoH{sub 2} state, while the b{sup 5}D (4d{sup 5}5s{sup 1}) state of Mo inserts spontaneously into H{sub 2} to form the bent {sup 5}B{sub 2} MoH{sub 2} ground state (R{sub e} = 1.67 {angstrom}, {theta}{sup c} = 116{degree}). The other electronic states of Mo such as a {sup 5}S, a {sup 5}D, etc. insert into H{sub 2} with small barriers while a {sup 3}P, a {sup 3}D, and a {sup 1}S states insert into H{sub 2} spontaneously. The {sup 7}A{sub 1} and {sup 5}B{sub 2} curves cross at {theta} {approximately} 35{degree} which should provide for a channel for {sup 7}S insertion in the Landau-Zener model. In the collinear (C{sub {infinity}{nu}}) mode of collision, the Mo({sup 7}S) atom forms only a weak complex with H{sub 2} while some of the quintet and triplet states form a stronger bond with H{sub 2}. Thus Mo reacts in the insertion mode more readily than the collinear mode. Mulliken population analyses and dipole moment analyses reveal considerable ionic character of the Mo-H bonds in MoH{sub 2}.

• DOE Contract Number: FG02-86ER13558
• OSTI ID: 6654266
• Journal Information: Journal of Physical Chemistry; (USA), Vol. 94:2; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
36 MATERIALS SCIENCE
ATOM-ATOM COLLISIONS
COMPUTER CALCULATIONS
CLUSTER MODEL
HYDROGEN
MOLYBDENUM
POTENTIAL ENERGY
SURFACE POTENTIAL
TRANSITION ELEMENT COMPOUNDS
ATOM COLLISIONS
COLLISIONS
ELEMENTS
ENERGY
MATHEMATICAL MODELS
METALS
NONMETALS
NUCLEAR MODELS
POTENTIALS
TRANSITION ELEMENTS
400200* - Inorganic
Organic
& Physical Chemistry
990200 - Mathematics & Computers
360104 - Metals & Alloys- Physical Properties