Use of the Isolated Atom Model in Quantitative Convergent Beam Electron Diffraction

Full text: Quantitative Convergent Beam Electron Diffraction (QCBED) is that experimental technique which probes the bonding in metals and ceramics with highest resolution, e.g. the first unequivocal determination of bonding in aluminium. At present QCBED uses background subtraction employing the Fourier transform of the electronic charge density of an isolated atom model (IAM) based on a Relativistic Hartree Fock atomic calculation. Computational crystalline material property programs establish the cohesive energy, one of the most fundamental quantities, by a super cell that mimics the IAM. This then enables the determination of various defect and surface energy properties. The present work employ IAMs found by WIEN2k to compare with QCBED results over a wide range of materials. The requirement of a charge density Fourier transform necessitates an all electron method such as WIEN2k. (author)