Electron diffraction intensity and high-resolution transmission electr
on microscopy (HRTEM) images are calculated for [001] InP crystals usi
ng the multi-slice method. The calculation is performed for two preval
ent models: (I) atoms within each slice are projected on their represe
ntative plane, and (II) atoms are equally shared out among slices and
projected on representative planes. Intensities of reflections such as
200, 220 and 400 for model II are appreciably different from those fo
r model I, which have very few errors. Forbidden reflections such as 1
10 and 310 appear only in the calculation for model I, changing abrupt
ly their intensity every slice in the unit cell, and deviate from Frie
del's law. The [001] HRTEM images, visualizing these results, also ind
icate that model II is inferior to model I in utility for quantitative
analysis.