Electron–molecule collision calculations using the R-matrix method

Electron-molecule scattering cross-sections. I. Experimental techniques and data for diatomic molecules

The BASECOL2012 database is a repository of collisional data and a web service within the Virtual Atomic and Molecular Data Centre (VAMDC, http://www.vamdc.eu). It contains rate coefficients for the collisional excitation of rotational, ro-vibrational, vibrational, fine, and hyperfine levels of molecules by atoms, molecules, and electrons, as well as fine-structure excitation of some atoms that are relevant to interstellar and circumstellar astrophysical applications. Submissions of new published collisional rate coefficients sets are welcome, and they will be critically evaluated before inclusion in the database. In addition, BASECOL2012 provides spectroscopic data queried dynamically from various spectroscopic databases using the VAMDC technology. These spectroscopic data are conveniently matched to the in-house collisional excitation rate coefficients using the SPECTCOL sofware package (http:// vamdc.eu/software), and the combined sets of data can be downloaded from the BASECOL2012 website. As a partner of the VAMDC, BASECOL2012 is accessible from the general VAMDC portal (http://portal.vamdc.eu) and from user tools such as SPECTCOL.

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BASECOL2012: A collisional database repository and web service within the Virtual Atomic and Molecular Data Centre (VAMDC)

The vibrationally inelastic cross sections are computed for the ν1 and ν3 modes of CF4 using the quantum mechanical adiabatic nuclear vibrations approximation for the dynamics and using a nonempirical local interaction potential for electrons as projectiles. The results from electron excitation are compared with available, albeit indirect, experimental data. The calculations confirm the dominance of the ν3 mode at energies below the electronic excitation as the main channel for vibrational heating of CF4 by electron impact.

http://iopscience.iop.org/article/10.1088/1367-2630/7/1/001/pdf

Vibrational excitation of CF4 by electron impact: a computational analysis

A new computational approach has been used to evaluate the rotationally summed, vibronically elastic integral cross sections from the scattering of slow electrons (energy ranging from 1.0 eV up to 40.0 eV) by tetrafluoromethane molecules in the gas phase. The various symmetry components have been analyzed using the exact static exchange approximation and also by including a nonempirical, model polarization potential employed before by our group. A comparison with earlier calculations and with existing experiments allows us to assign the symmetries of the shape resonances in the 5–30 eV energy region which are seen by experiments and are also shown by the present calculations.

A. Jain

Papers

The theory of electron scattering from polyatomic molecules