Intermediate energy cross sections for electron-impact vibrational-excitation of pyrimidine.
We report differential cross sections (DCSs) and integral cross sections (ICSs) for electron-impact vibrational-excitation of pyrimidine, at incident electron energies in the range 15-50 eV. The scattered electron angular range for the DCS measurements was 15°-90°. The measurements at the DCS-level are the first to be reported for vibrational-excitation in pyrimidine via electron impact, while for the ICS we extend the results from the only previous condensed-phase study [P. L. Levesque, M. Michaud, and L. Sanche, J. Chem. Phys. 122, 094701 (2005)], for electron energies ⩽12 eV, to higher energies. Interestingly, the trend in the magnitude of the lower energy condensed-phase ICSs is much smaller when compared to the corresponding gas phase results. As there is no evidence for the existence of any shape-resonances, in the available pyrimidine total cross sections [Baek et al., Phys. Rev. A 88, 032702 (2013); Fuss et al., ibid. 88, 042702 (2013)], between 10 and 20 eV, this mismatch in absolute magnitude between the condensed-phase and gas-phase ICSs might be indicative for collective-behaviour effects in the condensed-phase results.
School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia.
D B
DB
Jones
Instituto de Física Fundamental, CSIC, Serrano 113-bis, 28006 Madrid, Spain.
L
L
Ellis-Gibbings
Instituto de Física Fundamental, CSIC, Serrano 113-bis, 28006 Madrid, Spain.
G
G
García
Departamento de Física, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, Minas Gerais, Brazil.
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KL
Nixon
Departamento de Física, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, Minas Gerais, Brazil.
M C A
MC
Lopes
School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia.
M J
MJ
Brunger
D004583:Electrons; D011743:Pyrimidines / Q000737:chemistry*
D011743:Pyrimidines; C030986:pyrimidine