layer line

The mathematical apparatus of simulation diffraction by spiral nanotubes of arbitrary chemical composition, whose structure is described with the use of Bravais cells, is developed. The case of electron microdiffraction by a single nanotube is considered, the distributions of intensity in layer planes and lengthways layer lines are calculated.

The quantitative theory of diffraction by azimuthally ordered circular nanotubes of any chemical composition is offered. The pseudoorthogonality effect, earlier found out experimentally, is considered. The obtained results are compared with X-ray diffraction patterns of oriented preparations of chrysotile nanotubes.