Two-center interference effects for single electron capture in fast ion-molecule collisions

Total as well as angular-differential cross sections for single electron capture have been investigated in collision of bare ions ($$H^{+}$$, $$He^{2+}$$ and $$Li^{3+}$$) with hydrogen molecules at intermediate and high collision energies with special emphasis on finding interference effects to be exhibited by angular-differential cross sections. Here, we apply the first-order molecular target continuum distorted-wave approximation. Within the distorted-wave formalism, the one-active-electron model, developed to describe collisions with multi-electronic atomic targets, has been employed for the case of $$H_{2}$$ targets. Here, distortion in the final channel related to the Coulomb continuum state of the active electron in the field of residual molecular target ion is included. The present computed results are compared with the available experimental and other theoretical results. The total cross section is obtained by integrating over the projectile’s scattering angle and averaging over all the molecular orientations. The total capture cross sections for all the projectile ions have fair agreement with the experimental observations particularly at lower projectile energies. We have studied the differential cross sections at $$\theta _{\rho }=90^{\circ }$$, $$\phi _{\rho }=0^{\circ }$$, where $$\theta _{\rho }$$ and $$\phi _{\rho }$$ are the polar and azimuthal angles, respectively, of the molecular axis with respect to the incident direction at different impact energies. The interference between two capture amplitudes associated with two centers in the molecule has been found to be more pronounced at fixed orientation of the molecule.