Eur. Phys. J. D (2013) 67: 26
https://doi.org/10.1140/epjd/e2012-30473-9

Regular Article

Electron scattering from trans 1,3-butadiene molecule: cross-sections, oscillator strength and VUV photoabsorption cross-sections

¹ Observatorio do Valongo, Universidade Federal do Rio de Janeiro, 20080-090 Rio de Janiero, Brazil
² Instituto de Quimica, Universidade Federal do Rio de Janeiro, 21941-970 Rio de Janiero, Brazil
³ Departamento de Fisica, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, Brazil
⁴ Instituto de Quimica, Universidade Federal Fluminense, 24020-007 Niterói, Brazil
⁵ Instituto Federal de Educação, Ciência e Tecnologia, Rio de Janeiro, Brazil

^a e-mail: heloisa@astro.ufrj.br
^b e-mail: gerson@iq.ufrj.br

Received: 30 July 2012
Received in final form: 26 November 2012
Published online: 26 February 2013

Abstract

Electron energy-loss spectra for the butadiene molecule were measured in the scattering angular range of 2.0° to 8.0°, in an energy-loss range from 2 to 50 eV, using 1000 eV incident electrons. The absolute generalized oscillator strength (GOS) and inelastic cross section have been determined for the $\begin{array}{}{\mathrm{˜}}_{}\\ {\mathrm{X}}^{\mathrm{1}}\end{array}$A_g → 1¹B_u transition. The absolute elastic differential cross section was also determined spanning an angular range from 2.0° to 40.0°. From a small angle electron energy-loss spectrum, the optical oscillator distribution (photoabsorption spectrum) for the butadiene molecule was obtained in the 2 to 100 eV photon energy range. Accurate ab initio calculations have been performed, within the First Born Approximation, for generalized oscillator strength (GOS) and excitation energies for the $\begin{array}{}{\mathrm{˜}}_{}\\ {\mathrm{X}}^{\mathrm{1}}\end{array}$A_g → 1¹B_u and $\begin{array}{}{\mathrm{˜}}_{}\\ {\mathrm{X}}^{\mathrm{1}}\end{array}$A_g → 2¹A_g transitions. Our results emphasize the importance of using highly correlated wavefunctions and accurate methodologies in the calculation of the GOS for electron impact-induced electronic transitions in molecules.