Vibrational excitation of H₂O by electron impact

Abstract

We present results for the vibrational excitation of H 2 O by low-energy electrons (<10 eV). We calculate differential cross sections for the first excited states for all three modes using an R-matrix approach, at the static-exchange level, and the Chase approximation. Correction to the scattering amplitude for all partial waves (l > 3) is made using a closure approximation. The results are consistent with other theoretical treatments. For the bending mode there is agreement with two older experiments but disagreement with a more recent experiment at 7.5 eV. However, the present results for the stretch modes are less than the experimental values.

Excitation of the symmetric and antisymmetric stretch vibrations of H2O by electron impact

“…Details of the theoretical method were given by Moreira et al (2001). The calculations for the DCSs were performed with the UK R-matrix code (cf Morgan et al (1998)) and codes developed in Fribourg.…”

“…The theory assumes that the main interaction between the water molecule and the incoming electron is due to the dipole moment; thus the corrections to the scattering amplitude are done via a closure approximation. The DCS were calculated with the centre of mass of the water molecule at the origin of coordinates, unlike previous work, where the mass of the oxygen was taken to be infinity (Moreira et al 2001, Moreira 2000.…”

“…The excitation of the 010 and 100 modes has been calculated in the fixed nuclei, impulse approximation by Jain and Thompson (1983). The latter work has been improved and extended to include the (001) vibration by Moreira et al (2001), who also provide a more complete list of citations of earlier work. The theoretical studies have been reviewed and compared to experiments by Itikawa (1997).…”

Vibrational excitation of water by low-energy electron scattering: Calculations and experiments

“…The corresponding theoretical work has been constant but less intensive, due to the inherent computational difficulties in handling vibrationally inelastic dynamics within a physically correct framework. Thus, the more recent years have witnessed the vibrational close coupling treatment of Nishimura and Itikawa [12], the R-matrix calculations of Moreira et al [13] and the most recent extension of the discrete momentum representation method for vibrationally inelastic scattering of electrons for all the three normal modes of water [14].…”

Commission 14: Atomic and Molecular Data: (Donnees Atomiques Et Moleculaires)

“…These processes can be important through line excitation and cooling. Recent studies of excitation of molecules include H2O (Moreira, Thompson, & McLaughlin 2001), CO (Beegle et al 1999), C 0 2 (Eustatiu et al 2000), O j and TiO+ (Ballance, Berrington, k McLaughlin 1999), N 2 (Campbell et al 2001, Odagiri et al 2001, N j (Nagy et al 1999), and NO+ (Rabadan k Tennyson 1999).…”