Molecular treatment of He/sup +/+H collisions

Journal Article · Mon Jun 01 04:00:00 EDT 1981 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.23.2941· OSTI ID:6333678

Macias, A; Riera, A; Yanez, M

Total cross sections for the reactions /sup 4/He/sup +/(1s)+H(1s)..-->../sup 4/He/sup +/(1s)+H(2p), /sup 4/He/sup +/(1s) + H(1s)..-->../sup 4/He(1s2p /sup 1,3/P)+H/sup +/ are calculated in an impact-parameter formalism, for collision energies 0.5--30 keV, using a molecular approach. The molecular energies are calculated at large internuclear distances by a configuration-interaction method, and at short distances by a block-diagonalization method. The radial couplings between the molecular wave functions are evaluated exactly, and turn out to depend strongly on the choice of origin of electronic coordinates; as a consequence, the cross sections also depend on this choice. The effect of the anomalous rotational couplings which decrease like R/sup -1/ is shown to be negligible, and a method to integrate them is proposed in the Appendix. Choosing the center of mass as origin of electronic coordinates, we obtain good agreement with experimental data, but we find no a priori reason to favor this choice. As an important conclusion, the main effect of the so-called momentum-transfer problem, which is the origin dependence of the cross sections, is due to the form of the molecular wave functions at short internuclear distances.

• Research Organization: Departamento de Quimica Fisica y Quimica Cuantica, Centro Coordinado CSIC-UAM, Universidad Autonoma de Madrid, Canto Blanco, Madrid, Spain
• OSTI ID: 6333678
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 23:6; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
CENTER-OF-MASS SYSTEM
CHARGED PARTICLES
COLLISIONS
CONFIGURATION INTERACTION
COORDINATES
CROSS SECTIONS
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
FERMIONS
FUNCTIONS
HELIUM IONS
HYDROGEN
IMPACT PARAMETER
INELASTIC SCATTERING
ION COLLISIONS
ION-ATOM COLLISIONS
IONS
KEV RANGE
KEV RANGE 01-10
KEV RANGE 10-100
LEPTONS
MOLECULES
NONMETALS
SCATTERING
WAVE FUNCTIONS