Classical and semiclassical non-perturbative treatments of the electron transfer process in the collisional system proton-hydrogen involving initial excited states

Abstract

We investigate the total cross sections of the electron transfer process in the protonhydrogen collisional system involving initial excited states at impact energies in the 2.5 eV /u−100 keV /u range. The calculations are based on two non-perturbative treatments, namely the semiclassical Atomic Orbitals Close-coupling (SC-AOCC) approach and the Classical Trajectory Monte Carlo (CTMC) method. The results are presented and discussed for the collisions H + + H(n = 1, 2, 3) taking into account the degeneracy of each level in orbital momentum. We find that the SC-AOCC results show empirical n 3 and n 4 scaling laws at low and high impact velocities, respectively.

Atomic collisional data for neutral beam modeling in fusion plasmas

“…The WP-CCC results for p-H(1s) are from [27], for p-H(2s) are from [43]. The TC-BGM results are from [25] and the AOCC-1 are from [26], see also [24]. The 1s S-CTMC and the 1s C-QCTMC results are from [29,84].…”

“…Results for electron capture from H(2p 0 ) and H(2p 1 ) can be found in [25,42] and [24,26] for cross sections from H(2p), i.e. averaged over magnetic quantum numbers.…”

“…This process governs the beam attenuation in the plasma. Therefore, a large amount of experimental [10][11][12][13][14][15][16] and theoretical data [17][18][19][20][21][22][23][24][25][26][27][28][29] exists on this system, including the recommended data [6]. Theoretical calculations reproduce the experimental data reasonably well for the dominant channels for the processes such as excitation and electron capture.…”

Testing standard basis sets for direct ionizations: H+ + H at ELab = 0.1–100 keV

“…In the field of molecular physics, simulations of ion-molecule reactions mostly concentrated on electronic processes (CTs, DIs, and TEs), with little consideration, if not neglect, of nuclear processes (fragmentations, rearrangements, substitutions, etc.). [5][6][7][8][9][10][11][12][13][14][15] To treat electronic processes, numerous and diverse methods have been developed, such as the numerical solution of the time-dependent Schrödinger equation on a lattice, 5 the numerical solution of the time-dependent two-center Dirac equation with Dirac-Sturm basis functions, 6 various versions of the quantum close-coupling (CC) method [e.g., two-center atomic orbital CC (TCAO-CC), 7 molecular orbital (MO) CC (MO-CC), 8 semiclassical-atomic orbital CC (SC-AO-CC), 9 quantum mechanical convergent (QMC) CC (QMC-CC), 10 and one-center convergent (OCC) CC (OCC-CC) 11 ], the two-center basis generator method (TC-BGM), 12 the continuum distorted wave scattering method, 13 the first-order distorted wave theory (FODWT), 15 and classical and quasi-classical trajectory Monte Carlo methods (CTMC and QTMC, respectively). 9,14 These methods provided valuable insight into the investigated processes and predicted accurate properties.…”

“…[5][6][7][8][9][10][11][12][13][14][15] To treat electronic processes, numerous and diverse methods have been developed, such as the numerical solution of the time-dependent Schrödinger equation on a lattice, 5 the numerical solution of the time-dependent two-center Dirac equation with Dirac-Sturm basis functions, 6 various versions of the quantum close-coupling (CC) method [e.g., two-center atomic orbital CC (TCAO-CC), 7 molecular orbital (MO) CC (MO-CC), 8 semiclassical-atomic orbital CC (SC-AO-CC), 9 quantum mechanical convergent (QMC) CC (QMC-CC), 10 and one-center convergent (OCC) CC (OCC-CC) 11 ], the two-center basis generator method (TC-BGM), 12 the continuum distorted wave scattering method, 13 the first-order distorted wave theory (FODWT), 15 and classical and quasi-classical trajectory Monte Carlo methods (CTMC and QTMC, respectively). 9,14 These methods provided valuable insight into the investigated processes and predicted accurate properties. However, their way of representing the continuous and unbound states of electrons involved in DIs remains rather alien to quantum chemistry praxis (e.g., representations via numerical lattices 5 and distorted scattering waves 13 ).…”