Crystal Lattice Structures:	Creation Date:  9 Apr 2002
	Last Modified: 21 Oct 2004

A Hypothetical cI32 Austenite Structure

You can now

• see the structure from several perspectives;
• examine the structure with an external viewer; or
• download the coordinates of the atoms in these pictures in XYZ format.
• visualize the structure (Uses the JMOL Applet)

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• Austenite is steel with an fcc structure. This structure represents one possible ordering which might be found in an Fe-Ni-Cr steel. Note that it is not meant to represent a real steel.
• Replacing the Ni atoms on the (6b) sites by Cr turns this into a Cu₃Au (L1₂) structure.
• Removing the (2a) atom gives a structure which can be used to calculate the vacancy formation energy in fcc elemental solids.
• If we set the y parameter for the (24h) sites to ¼ the atoms are on the sites of an fcc lattice with lattice constant a_fcc = ½ a.

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• Prototype: CrFe₁₂Ni₃ (hypothetical)
• Pearson Symbol: cI32
• Space Group: Im3m (Cartesian and lattice coordinate listings available)
• Number: 229
• Primitive Vectors:

  A1	=	-½ a X + ½ a Y + ½ a Z
  A2	=	+ ½ a X - ½ a Y + ½ a Z
  A3	=	+ ½ a X + ½ a Y - ½ a Z

• Basis Vectors:

  B1	=		0		(Cr)	(2a)
  B2	=	+ 2 y A1 + y A2 + y A3	=	+ y a Y + y a Z	(Fe)	(24h)
  B3	=	+ y A1 + 2 y A2 + y A3	=	+ y a X + y a Z	(Fe)	(24h)
  B4	=	+ y A1 + y A2 + 2 y A3	=	+ y a X + y a Y	(Fe)	(24h)
  B5	=	- y A2 + y A3	=	+ y a Y - y a Z	(Fe)	(24h)
  B6	=	- y A1 + y A3	=	+ y a X - y a Z	(Fe)	(24h)
  B7	=	- y A1 + y A2	=	+ y a X - y a X	(Fe)	(24h)
  B8	=	+ y A2 - y A3	=	- y a Y + y a Z	(Fe)	(24h)
  B9	=	+ y A1 - y A3	=	- y a X + y a Z	(Fe)	(24h)
  B10	=	+ y A1 - y A2	=	- y a X + y a X	(Fe)	(24h)
  B11	=	- 2 y A1 - y A2 - y A3	=	- y a Y - y a Z	(Fe)	(24h)
  B12	=	- y A1 - 2 y A2 - y A3	=	- y a X - y a Z	(Fe)	(24h)
  B13	=	- y A1 - y A2 - 2 y A3	=	- y a X - y a Y	(Fe)	(24h)
  B14	=	+ ½ A2 + ½ A3	=	+ ½ a X	(Ni)	(6b)
  B15	=	+ ½ A1 + ½ A3	=	+ ½ a Y	(Ni)	(6b)
  B16	=	+ ½ A1 + ½ A2	=	+ ½ a Z	(Ni)	(6b)

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Structures indexed by: Strukturbericht Symbol Pearson Symbol Space Group Prototype

This is a mirror of an old page created at the Naval Research Laboratory Center for Computational Materials Science The maintained successor is hosted at http://www.aflowlib.org/CrystalDatabase/ and published as M. Mehl et al., Comput. Mater. Sci. 136 (Supp.), S1-S828 (2017).