Aspherical electron scattering factors and their parameterizations for elements from H to Xe

The formalism for, and the values of, aspherical electron scattering factors using relativistic wavefunctions are presented. The parameterizations of electron form factors valid for a full range of scattering vectors from 0.0 to 6.0 Å^-1 were obtained for atoms with atomic number 1 (H) to 54 (Xe) by fitting a linear combination of Gaussian functions. Eight Gaussians were needed to achieve high-quality fittings. The tabulated aspherical p- and d-orbital parameters are invaluable for probing orbital electrons and calculating high-resolution electron microscopy images and diffractions, especially those involving interfaces and defects.