Ab initio calculations of low-energy electron scattering by HCN molecules: Dependence on internuclear distance in linear geometry

Journal Article · Wed Jan 15 04:00:00 EST 1986 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.450570· OSTI ID:6336871

Jain, A; Norcross, D W

Low-energy electron scattering with HCN molecules is studied in the SEP (static-exchange plus parameter-free polarization potential) model as a function of both bond (CH and CN) stretches. A /sup 2/Pi resonance at the equilibrium geometry behaves very similarly to the CO /sup 2/Pi resonance as the CN bond is stretched; the corresponding HCN/sup -/(/sup 2/Pi) potential surface seems to cross the neutral curve (HCN, /sup 1/..sigma../sup +/) around 2.9 a.u. of CN distance. In /sup 2/..sigma.. symmetry, where no shape resonance is present at equilibrium geometry, a broad resonance appears when the CH or CN bonds are stretched well beyond the equilibrium position; the former appears to cross the /sup 1/..sigma../sup +/ curve at about 2.8 a.u., i.e., just below the H+CN/sup -/ asymptote, the latter to approach the neutral curve much more slowly and tangentially. Structure interpreted as a Pi resonance in vibrational excitation, and as necessarily of ..sigma.. character in dissociative attachment to the lowest anion--neutral asymptote, can be explained as due to the mixing of the lowest linear /sup 2/Pi and /sup 2/..sigma.. resonances through bending (the Renner--Teller effect) and the peculiarity (cusp behavior) associated with anion--neutral curve crossings in polar molecules.

• Research Organization: Joint Institute for Laboratory Astrophysics, University of Colorado and National Bureau of Standards, Boulder, Colorado 80309-0440
• OSTI ID: 6336871
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 84:2; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
COLLISIONS
CYANIDES
DISSOCIATION
ELASTIC SCATTERING
ELECTRON ATTACHMENT
ELECTRON COLLISIONS
ELECTRON-MOLECULE COLLISIONS
HYDROCYANIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
MOLECULE COLLISIONS
SCATTERING