Extension of the single-channel MCHF method to include multichannels

Abstract

The multiconfiguration Hartree–Fock (MCHF) method for single open channel has been extended to include multi-open channels. The coupled integro-differential equations satisfied by the radial wavefunctions of the multi-open channels associated with the scattering of electrons by atoms and ions at low energies are solved completely numerically self-consistently in the MCHF approximation to obtain the required linearly independent solutions. The asymptotic scattering parameters obtained from these solutions are used to calculate cross sections. The electron correlation and polarization effects which are very important for scattering of electrons at low energies can be obtained completely ab initio through the configuration interaction procedure. The extended method is now capable of performing calculations for both elastic and inelastic scattering processes. As a test case, we have calculated contributions to both elastic and inelastic cross sections for scattering of electrons from hydrogen and helium atoms as well as ionized helium at a few low energies for few partial waves including a few open channels. Our results are compared with similar data obtained by other existing approximate methods and are found to be in excellent agreement confirming a successful extension.

Small device-to-device variation of 6,13-bis(triisopropylsilylethynyl)pentacene field-effect transistor arrays fabricated by a flow-coating method

“…defines the Nelectron target wave function which has configuration γ i , energy E i and the term value L S i i and F k l i i describes the single electron continuum wave function which has kinetic energy k i 1 2 2 (in atomic units) and orbital angular momentum l i and when these two wave functions are coupled together to form an antisymmetric wave function for the N ( 1) + electron configuration, the total wave function at energy E E k 2 i 2 = + and term value LS can be expressed, in the HF approximation, as [15] ( )…”

Low-energy electron-impact ionization of the helium atom using the multiconfiguration Hartree-Fock method

“…The description of the multichannel MCHF method for the bound and continuum wave functions was reported earlier [17]. We provide here a brief description of the method.…”

“…All these methods provide different accurate descriptions of the final-state wave functions. Recently, we have studied [16] TDCSs of H for 4 eV excess energy shared both equally and unequally by the two final-state continuum electrons for θ 12 = π geometry using Hartree-Fock (HF) [17] and the screening potential (SP) approximations [6,18,19]. Later we investigated [20] the application of the HF approximation to on the TDCS of H at several incident energies for the case in which two final-state continuum electrons leave in opposite directions.…”

Hartree-Fock studies of the triple differential cross section for electron-impact ionization of the hydrogen atom

“…The multi-channel multi-configuration Hartree-Fock (MCHF) method is described earlier [15]. The total wave function in the HF approximation [11] at energy E = E i + k 2 /2 and term value LS can be expressed as [15]…”

“…The set of radial functions describing the continuum orbitals are determined variationally. These radial functions are the solutions of the integro-differential equations of the form [15],…”