Theoretical Studies On Low-energy Electron Scattering Cross Sections Of Several Molecules And Resonances

Electron scatering,one of the fundamental processes in physics and chemistry,is very important in atmospheric physics,plasmas physics,inertial confinement fusion,materials chemistry,catalyze and so on.In this article,we use R-matrix method to deal with the low-energy electron collisions with methyleneimine and ketene.R-matrix calculations on electron-H2 CNH collisions are presented within the static exchange plus polarization,and close-coupling approximations.A ?* shape resonnace was predicted at 1.65 and 1.95 eV.In close-coupling model,the electron-impact excitation cross sections for first three low-lying electronic excited states of H2 CNH molecule from the ground state of H2 CNH molecule have been calculated for the first time.The differential and momentum-transfer cross sections along with effective collision frequency over a wide electron temperature range(200–30000 K)are also computed.Low-energy electron collisions with ketene are studied in the correlated and uncorrelated approximations using the R-matrix method.A series of target calculations is performed with different basis set for the obtaining of the reliable target wave function.In the scattering calculations,we find two low-lying ?* shape resonances belonging to 2B1 and 2B2 symmetry,respectively,and two higher-energy resonances of 2B1 symmetry,one core-excited shape resonance and one Feshbach resonance.The Born approximation is applied for the elastic and dipole-allowed transitions to account for the contribution of partial waves higher than L = 4 to obtain converged cross sections.Our results are compared with cross sections of CO2 calculated at the same level of complexity using the R-matrix method.The effective collision frequencies over a wide electron temperature range(100–30000 K)are calculated using the data of the momentum-transfer cross section.In this paper,Chapter 1 describes the background of this dissertation,including the domestic and foreign research for electron-polyatomic scattering.In Chapter 2,we introduce the R-matrix theory in detail,including the evolution of R-matrix and derivation of basic equations and formal definition of the R-matrix.Finally in this chapter,the UK molecular R-matrix coads are described.In Chapter 3 and Chapter 4,we employ the R-matrix method to investegate the electron scattering by methyleneimine and ketene respectively.