Multichannel-quantum-defect-theory treatment of reactive collisions between electrons and BeH+

Abstract

A theoretical treatment of dissociative recombination (DR), vibrational excitation (VE) and vibrational deexcitation (VdE) of the BeH + ion in its four lowest vibrational states (X 1 Σ + , v + i = 0, 1, 2, 3) is reported. The multichannel quantum defect theory is used to determine cross sections and rate coefficients. Three electronic symmetries of BeH-2 Π, 2 Σ + , and 2 ∆-have been included in the calculations. At low energies the DR is dominated by capture into states of 2 Π symmetry. Satisfactory agreement with results obtained using the wave packet approach is reached at intermediate energies despite significant differences at low energies. Cross sections and rate coefficients suitable for the modeling of the kinetics of BeH + in fusion plasmas and in the stellar atmospheres are presented and discussed.

Reactive collisions of electrons with H2+, HD+, BeH+, BeD+ and SH+

“…In this section, we have expanded our previous studies on BeH + [14,15] to BeD + [16] and BeT + cations. Figure 7 shows the Maxwell rate coefficients of excited (v i + = 12-17) BeD + , significantly depending on the initial vibrational level of the molecular ion.…”

Advances in the MQDT approach of electron/molecular cation reactive collisions: High precision extensive calculations for applications

“…5, where the direct mechanism has been considered exclusively, since as shown in [34], the indirect process is very weak for the electron-impact processes involving this ion. The cross sections for the two isotopomers show the same patterns and thresholds, due to the consecutive opening of different dissociation and ionization channels, while the difference between them is attributed to the different vibrational level densities, due to the different reduced masses.…”

“…Using the molecular data on superexcited BeH states available from our previous studies [33,34] computations of cross sections and rate coefficients for all the vibrational states of the target have been 02003-p.6 performed for the electron-impact DR, vibrational excitation (VE) and de-excitation (VdE) of BeH + at low energy (i.e. below the ion dissociation threshold).…”

Study of reactive collisions between electrons and molecular cations using multichannel quantum defect theory: Application to HD+ and BeH+

“…Using the set of molecular data for BeH + already used in [19], we have produced DR cross sections for vibrational excited states of BeH + , taking into account the direct and indirect processes [19]. We have explored the energy range 10 −3 -10 -1 eV of the incident electron, which corresponds to a total energy of the system far below the dissociation limit of its ground electronic state.…”

“…The theoretical treatment of dissociative recombination (DR) of the BeH + ion in its excited vibrational states has been also performed. In this case we have used a non-rotational approach [19] because the accuracy of molecular data is lower than in the case HD + /HD system.…”