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Title: Inelastic processes in collisions of H{sup +} ions with C, N, O, and Si atoms below 1 keV

Journal Article · · Physical Review A
 [1]; ; ;  [2]
  1. School of Allied Health Sciences, Yamaguchi University, Ube, Yamaguchi 755 (Japan)
  2. Theoretische Chemie, Bergische Universitaet-Gesamthochschule Wuppertal, D-42097 Wuppertal (Germany)

Electron capture in collisions of C, N, O, and Si atoms with H{sup +} ions is studied theoretically based on a molecular representation within a fully quantum framework by including six molecular channels both for the ground and excited states for the [H{sup +}+C] system, and four channels for the ground-state [H{sup +}+N] and [H{sup +}+O] systems. For the [H{sup +}+Si] system, we employed the molecular representation both in fully quantum and semiclassical frameworks to investigate electron capture at higher energy as well. The {ital ab initio} potential curves and nonadiabatic coupling matrix elements for all these systems are obtained from multireference single- and double-excitation configuration interaction calculations. For all systems, the effect of excited atoms on electron capture is examined in addition to that from the ground state. Because of a small asymptotic energy defect (near-resonant processes) between the initial and closest electron capture channels for almost all systems, electron capture cross sections from the ground-state atoms are large with values of approximately 10{sup {minus}16}{minus}10{sup {minus}15}cm{sup 2} for all systems at above 100 eV. Corresponding rate coefficients are found to be much smaller than those previously reported for the NH{sup +} and OH{sup +}, but, on the contrary, found to be larger by a few orders of magnitude than the previously estimated value for the SiH{sup +} system. Those from excited states are also found to be extremely efficient for all cases. {copyright} {ital 1997} {ital The American Physical Society}

OSTI ID:
530931
Journal Information:
Physical Review A, Vol. 55, Issue 4; Other Information: PBD: Apr 1997
Country of Publication:
United States
Language:
English