FINITE-DIFFERENCE METHOD FOR THE CALCULATION OF LOW-ENERGY-ELECTRON DIFFRACTION

A new scheme of calculation avoiding the muffin-tin approximation is presented for low-energy-electron diffraction. The finite-difference method is then used to solve the Schrodinger equation. A simple superposition potential and a nonuniform three-dimensional grid of points yields satisfactory experiment-theory agreement for the Cr(100)-(1 x 1)N surface, with geometrical parameter values close to the ones found in a standard study. An optimization of the charge exchange gives a 1.3 electron transfer from chromium to nitrogen.