MASAP: A package for atomic scattering amplitude in solids
Résumé
We present the MsSpec Atomic Scattering Amplitude Package (MASAP), composed of a computation program and graphical interface to generate atomic scattering amplitude (ASA) an atom, either isolated or embedded in environment, at any chosen energy impinging electron up ≈15 KeV. The ASA is calculated using effective, complex optical potential which provides damping effects process fully relativistic framework. Optionally, scalar non-relativistic approximations are also available assess their applicability given problem. In order describe propagation solids we suggest replace ASA's based on Plane Waves (PW) with effective curved Spherical (SW) truncated-overlapped potentials Muffin-Tin (MT) type constructed according Mattheiss prescription. user generates not only data files providing Differential Cross Sections (DCS) but related quantities such as total Section (CS), both elastic inelastic, tl-matrices phase shifts. found general that imaginary part enhances DCSs forward direction compared same without part, feature theorem, gives rise lower intensity all other directions expected due effect potential. show differential transport for aluminum gold atoms isolation crystals Face-Centered-Cubic (FCC) structure.