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In crystallography, a Greninger chart[1] /ˈɡrɛnɪŋər/ is a chart that allows angular relations between zones and planes in a crystal to be directly read from an x-ray diffraction photograph.
The Greninger chart is a simple trigonometric tool to determine g and d for a fixed sample-to-film distance. (If one uses a 2-d detector the problem of determining g and d could be solved mathematically using the equations which generate the Greninger chart) A new chart must be generated for different sample to detector distances. (2s is 2q for the diffraction peak and tan m is x/y for the Cartesian coordinates of the diffraction peak.) The Greninger chart gives directly the two angles needed to plot poles on the Wulff net. It is critical to keep track of the relative arrangement of the sample to the film, if photographic film is used then this is achieved by cutting the corner of the film. For Polaroid film one must make a note of the arrangement of the face of the film in the camera.
See also
[edit]References
[edit]- ^ It is named after Alden Buchanan Greninger (17 September 1907, Glendale, Oregon – 20 April 1998).
Sources
[edit]- Greninger A. B. (1935). Zeitschrift für Kristallographie 91: 424.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction