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Difference between revisions of "Weiss parameters"

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<Font color="blue"> Paramètres de Weiss</Font> (''Fr''). <Font color="red"> Weiss-Parameter </Font> (''Ge''). <Font color="green"> Parámetros de Weiss</Font> (''Sp''). <Font color="brown"> Параметры Вайс </Font> (''Ru''). <Font color="black"> Parametri di Weiss</Font> (''It''). <Font color="purple"> ワイスパラメーター</Font> (''Ja'')
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<Font color="blue"> Paramètres de Weiss</Font> (''Fr''). <Font color="red"> Weiss-Parameter </Font> (''Ge''). <Font color="green"> Parámetros de Weiss</Font> (''Sp''). <Font color="brown"> Параметры Вайс </Font> (''Ru''). <Font color="black"> Parametri di Weiss</Font> (''It''). <Font color="purple"> ワイスパラメーター</Font> (''Ja'').
  
  
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Weiss parameters are the reciprocal of Miller indices, each followed by the corresponding axis symbols.
 
Weiss parameters are the reciprocal of Miller indices, each followed by the corresponding axis symbols.
  
'''Example'''. Weiss parameters 2a:3b:1c indicate that a face intercepts the '''a''' axis at twice the a<sub>o</sub> units and the '''b''' axis at three times b<sub>o</sub> units as it cuts the '''c''' axis in c<sub>o</sub> units. The first plane of the family to which this face belongs has intercepts at 1/3, 1/2 and 1/6 on '''a''', '''b''', and '''c''' respectively, so that the corresponding Miller indices are (326).
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'''Example'''. Weiss parameters 2''a'':3''b'':1''c'' indicate that a face intercepts the '''a''' axis at twice the ''a<sub>o</sub>'' units and the '''b''' axis at three times ''b<sub>o</sub>'' units as it cuts the '''c''' axis in ''c<sub>o</sub>'' units. The first plane of the family to which this face belongs has intercepts at 1/3, 1/2 and 1/6 on '''a''', '''b''', and '''c''' respectively, so that the corresponding Miller indices are (326).
  
=== Reference ===
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== Reference ==
Weiss, C.S. (1817). Ueber eine verbesserte Methode für die Bezeichung der verschiedenen Flächen eines Krystallisationssystemes; nebst Bemerkungen über den Zustand von Polarisierung der Seiten in den Linien der krystallinischen Structur. ''Abhandlungen der Königlichen Akademie der Wissenschaften in Berlin'', 286-336 ([https://babel.hathitrust.org/cgi/pt?id=umn.31951d00016117y;view=1up;seq=304 digitized version available online]).
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Weiss, C. S. (1817). ''Abhandlungen der Königlichen Akademie der Wissenschaften in Berlin'', 286-336. ''Ueber eine verbesserte Methode für die Bezeichung der verschiedenen Flächen eines Krystallisationssystemes; nebst Bemerkungen über den Zustand von Polarisierung der Seiten in den Linien der krystallinischen Structur'' ([https://babel.hathitrust.org/cgi/pt?id=umn.31951d00016117y;view=1up;seq=304 digitized version available online])
  
 
[[Category:History of crystallography]]
 
[[Category:History of crystallography]]
 
[[Category:Morphological crystallography]]
 
[[Category:Morphological crystallography]]

Revision as of 11:38, 20 May 2017

Paramètres de Weiss (Fr). Weiss-Parameter (Ge). Parámetros de Weiss (Sp). Параметры Вайс (Ru). Parametri di Weiss (It). ワイスパラメーター (Ja).


The Weiss parameters, introduced by Christian Samuel Weiss in 1817, are the ancestors of the Miller indices. They give an approximate indication of a face orientation with respect to the crystallographic axes, and were used as a symbol for the face.

Weiss parameters are the reciprocal of Miller indices, each followed by the corresponding axis symbols.

Example. Weiss parameters 2a:3b:1c indicate that a face intercepts the a axis at twice the ao units and the b axis at three times bo units as it cuts the c axis in co units. The first plane of the family to which this face belongs has intercepts at 1/3, 1/2 and 1/6 on a, b, and c respectively, so that the corresponding Miller indices are (326).

Reference

Weiss, C. S. (1817). Abhandlungen der Königlichen Akademie der Wissenschaften in Berlin, 286-336. Ueber eine verbesserte Methode für die Bezeichung der verschiedenen Flächen eines Krystallisationssystemes; nebst Bemerkungen über den Zustand von Polarisierung der Seiten in den Linien der krystallinischen Structur (digitized version available online)