Positron total cross sections for collisions with O2, H2O and CH4 in energy range from 30 to 3000eV
30-3000eV的正电子被O2、H2O及CH4散射的总截面计算

Total (elastic plus inelastic) cross sections for the scattering of positrons by three molecules (O2, H2O and CH4) in the energy range from 30 to 3000eV are calculated using the additivity rule model at Hartree-Fock level. A complex optical model potential modified by incorporating the concept of bonded atom which takes into consideration the overlapping effect of electron clouds between two atoms in a molecule is firstly employed for the TCS calculation of positron-molecule scattering. The quantitative total cross sections are compared with those obtained in experiments and other theories wherever available, and good agreement is obtained in the energy range from 30 to 3000eV. It is shown that the additivity rule model together with the modified complex optical model potential is completely suitable for the total cross section calculations of the positron-molecule scattering.