CRYSTALS, DATABASES, COMPUTER software, CRYSTALLINE electric field, ORGANIC chemistry, and MATHEMATICAL models
Abstract
In order to establish the effect of exchanging one functional group by another on the crystal structure, one would like to be able to search the Cambridge Structural Database for all pairs of crystal structures where this substitution has been made. A program called GRX (group exchange) was written for that purpose. [ABSTRACT FROM AUTHOR]
OPTICAL diffraction, MONTE Carlo method, PATTERSON function, MATRIX inversion, CHEMICAL decomposition, and ORGANIC chemistry
Abstract
The success of ab initio crystal structure solution by powder diffraction data is strictly related to the quality of the integrated intensity estimates. A new method that is able to improve the pattern decomposition step has been developed. It combines the inversion of a suitably modified Patterson map with the use of the Hamming codes [13,10] and [40,36] in order to explore more decomposition trials. The new approach has been introduced in EXPO2005, an updated version of EXPO2004, and successfully applied to a set of known organic and inorganic structures. [ABSTRACT FROM AUTHOR]
General Biochemistry, Genetics and Molecular Biology, Structure analysis, Crystallography, General chemistry, Materials science, and Solid-state chemistry
Abstract
This contribution describes a 30-year experience of teaching a general course in solid-state chemistry for undergraduates, which introduces at the same time the main concepts of crystallography, gives an introduction to structure analysis techniques, and makes links to courses in inorganic chemistry, organic chemistry and biochemistry. Such a combination can be beneficial for bringing the fundamentals of crystallography (basics and techniques) closer to its `users' – chemists, materials scientists, biologists – and can be considered as an attempt to create a course in `applied crystallography'. The aim of the course is to teach chemists which chemical information can be retrieved from a crystal structure and how. This is complementary to more generally accepted courses, which teach how to obtain structural information and to describe crystal structures.
