Electron crystallography at atomic resolution: the structure of the odd-chain paraffin n-tritriacontane.

The crystal structure of the odd-chain paraffin, n-tritriacontane, nC33H68, is determined directly by using low-dose electron microscope images and electron diffraction intensity data from epitaxially grown microcrystals. Phases of the most intense "polyethylene" reflections are determined from triplet structure-invariant relationships often used in X-ray crystallography. Low-dose electron microscopic images provide phases of the low-angle "lamellar" reflections and these can be used with one-dimensional structure-invariant relationships to determine other phases on the 00l reciprocal row. The phase set is sufficient to calculate an electrostatic potential map which is directly interpretable as a structure image at atomic resolution.