Abstract
As shown in an accompanying paper, the quantitative use of electron diffration data from slightly bent, thin microcrystals for structure analysis is impeded when a long unit cell axis is parallel to the incident beam. A total crystallographic analysis is allowed, on the other hand, if a shorter cell edge parallels this direction so that the largest Patterson components along this vector are not severely spread out by slight crystal bending.Because of favored van der Waals interactions, typical solution crystal growth of molecular organic compounds causes the longest unit cell axis to lie approximately perpendicular to the best developed crystal face. A crystal growth forcing the longest unit cell axis to lie in this direction, on the other hand, can be realized by epitaxy, the earliest demonstration for polymethylene chain materials given by Willems. Although the use of cleaved salt crystal faces has long been popular for nucleation of epitaxial growth, organic substrates, such as naphthalene, present certain advantages.
Publisher
Cambridge University Press (CUP)