Twisted-electron-impact single ionization of an H2O molecule by multicenter distorted-wave calculations

We report theoretical investigation of the twisted-electron-impact single-ionization dynamics of an H2O molecule. The triple-differential cross sections for 1b1, 3a1, 1b2, and 2a1 orbitals are obtained by a twistedelectron-impact multicenter distorted-wave method. The coplanar asymmetric kinematic condition is adopted at incident electron energy Ei = 250 eV and ejected electron energy Ee = 10 eV. By integrating the impact parameter, all possible rotation angles ??k of the projectile are averaged for the triple-differential cross section, which is independent of the orbital angular momentum and varies as a function of opening angle ??k. The results show that the ionization by a plane-wave projectile is more likely than by a twisted-electron projectile if the scattering angle is smaller than a critical value. However, when the scattering angle exceeds the critical point, the twisted-electron projectile can possess higher ionization probability, which will reach a maximum when the opening angle numerically approaches the scattering angle.