Crystal truncation effects

Crystal data and details of data collection, data reduction and final refinement are reported in Table 1. The procedure for data collection and processing, which included a correction for scan-truncation effects, were similar to those recently described for syn-l,6 8,13-biscarbonyl[14]annulene [10] and citrinin [11], Figure 1 shows the numbering scheme adopted in the present analysis. 

Consider the same N molecules at rest in a perfectly ordered infinite crystalline array with one molecule in the asymmetric unit. All molecules are equal, and surface or truncation effects are neglected, so the following discussion refers to a bulk crystal. Assuming for the moment that the intermolecular potential is pairwise additive, e.g. in the atom-atom potential approximation, the packing potential energy, PPE, or the interaction energy of any reference molecule m with the surrounding molecules n, is a sum of molecule-molecule terms, each of which is in turn a sum of atom-atom terms ... 

One of the more important uses of OM is the study of crystallization growth rates. K. Cermak constructed an interference microscope with which measurements can be taken to 50° (Ref 31). This app allows for study of the decompn of the solution concentrated in close proximity to the growing crystal of material such as Amm nitrate or K chlorate. In connection with this technique, Stein and Powers (Ref 30) derived equations for growth rate data which allow for correct prediction of the effects of surface nucleation, surface truncation in thin films, and truncation by neighboring spherulites... 

D. M. York, T. A. Darden, and L. G. Pedersen, The effect of long-range electrostatic interactions in simulations of macromolecular crystals - a comparison of the Ewald and truncated list methods, J. Chem. Phys., 99 (1993), 8345-8348. 

Tanemura et al. examined crystallization in a liquid of soft spheres and found both fee and bcc structures. They used the method of Voronoi polyhedra to characterize the evolving solid clusters. Hsu and Rahman extended the use of Voronoi polyhedra in a systematic study of the effect of potential on the structure observed. They found that a model rubidium potential always crystallized to a bcc structure, while a truncated rubidium, Lennard-Jones,... 

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