Cross sections for rotational excitations of NH3, PH3, AsH3, and SbH3 by electron impact

We report elastic and rotationally inelastic cross sections for e(-)-XH3 co llisions (X: N, P, As, Sb) at the static-exchange level of approximation. T he energy range was from 7.5 up to 30 eV. Our fixed-nuclei scattering ampli tudes were obtained through the Schwinger multichannel method with pseudopo tentials (SMCPP) [M. H. F. Bettega, L. G. Ferreira, and M. A. P. Lima, Phys . Rev. A 47, 1111 (1993)]. The rotational cross sections were obtained with the help of the adiabatic-nuclei-rotation approximation. There is good agr eement with available experimental elastic cross sections. In order to impr ove rotational cross sections at small scattering angles for the dipole-all owed 00-->10 rotational excitation, we have combined the SMCPP and the firs t Born approximation of the full interaction potential and also of the dipo le moment potential. To our knowledge this is the first time that rotationa l excitation cross sections for these molecules are reported. (C) 1999 Amer ican Institute of Physics. [S0021-9606(99)02005-X].