Efficient beam-selection criteria in quantitative convergent beam electron diffraction

New criteria to identify significant beams in many beam dynamical calculations are introduced. The new beam selection criteria are used in a structure factor refinement procedure where the correct identification of the most significant beams is crucial. Beams are divided into two categories. Strong beams are included in the dynamical calculations through diagonalisation. The effects of weak beams are successfully described by Bethe-perturbation of the dynamical matrix. The new method is compared to existing algorithms and found favourable, both in terms of computing time and stability in calculations.