Nowe metody w badaniach struktur polikryształów
Journal Title: Wiadomości Chemiczne - Year 2014, Vol 68, Issue 5
Abstract
In this chapter, information on good laboratory practice in the field of structural powder diffractometry has been collected. The authors attempt to describe how to plan a measurement, how to find the cell parameters, how to build a model of the structure, and how to refine and verify it. There are many methods and procedures which lead to solving a crystal structure. However, the experience of recent years shows that, in the case of many materials, an investigator has to attempt the problem of structure solution using many different methods. The software is easily available (from ‘trial and error’ or classic to sophisticated modern approaches), as is a lot of good equipment. On the other hand, the complexity of the structures studied using powder diffraction methods is continually increasing. No description of any methods of research other than diffraction techniques is presented. We have also focused on polycrystalline materials. Amorphous substances and methods using the formalism of ‘pair distribution functions’ are beyond the scope of this paper. New methods of structural studies (including algorithms from research described in the literature, even if their applicability has been relatively slight) were treated with particular attention. In addition to the description of methods, we also collected some useful (in our opinion) information about available software and crystallographic databases.
Authors and Affiliations
Wiesław Łasocha, Katarzyna Luberda-Durnaś
Oddziaływanie elektronów z cząsteczkami o biologicznym znaczeniu
Recent years have witnessed an increase of the interest in the studies of the interaction of electrons with biologically relevant molecules. This has been mainly motivated by the seminal work, where it has been demonstra...
Biblioteki związków chemicznych
Over the past decade one can observe a scientific revolution taking place resulting in an explosion of new biotechnologies. Moreover, with the end of the human genome project and following expansion of the extensive gene...
Wpływ anestetyków wziewnych na modelową błonę biologiczną
General anesthesia is defined as impairment of the central nervous system (UON) caused by intravenous or volatile anesthetics. The state of loss of consciousness or even amnesia and the disappearance of perception into e...
Borowce jako centra kwasów Lewisa w oddziaływaniach międzycząsteczkowych : porównanie z wiązaniami wodorowymi
The triel bonds are analyzed and compared with the hydrogen bond interaction. The triel bonds belong to the class of interactions that are named as the σ-hole and π-hole bonds. The σ-hole bond is an interaction between t...
Haloizyt–naturalny absorber promieniowania elektromagnetycznego
The question about the harmfulness of electromagnetic radiation is ever more often raised in scientific discussions it is also interesting for the public. Unfortunately, there are no easy answers and no settled opinion....