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

A Hypothetical cP32 Austenite Structure

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• 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.
• Removing the (1a) atom gives a structure which can be used to calculate the vacancy formation energy in fcc elemental solids.
• If we set x₁ = x₂ = ¼, the atoms are on the sites of an fcc lattice with lattice constant a_fcc = ½ a.
• Replacing the Fe-III atom by a Cr atom, while keeping all of the other atoms the same, reduces this configuration to our hypothetical cI32 austenite structure.

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• Prototype: CrFe₂₅Ni₆ (hypothetical)
• Pearson Symbol: cP32
• Space Group: Pm3m (Cartesian and lattice coordinate listings available)
• Number: 221
• Primitive Vectors:

  A1	=	a X
  A2	=	a Y
  A3	=	a Z

• Basis Vectors:
  Since this is a simple cubic lattice, we'll leave off the lattice coordinate expression of the basis vectors:

  B1	=	0	(Cr)	(4a)
  B2	=	+ x1 a Y + x1 a Z	(Fe-I)	(12i)
  B3	=	+ x1 a X + x1 a Z	(Fe-I)	(12i)
  B4	=	+ x1 a X + x1 a Y	(Fe-I)	(12i)
  B5	=	+ x1 a Y - x1 a Z	(Fe-I)	(12i)
  B6	=	+ x1 a X - x1 a Z	(Fe-I)	(12i)
  B7	=	+ x1 a X - x1 a Y	(Fe-I)	(12i)
  B8	=	- x1 a Y + x1 a Z	(Fe-I)	(12i)
  B9	=	- x1 a X + x1 a Z	(Fe-I)	(12i)
  B10	=	- x1 a X + x1 a Y	(Fe-I)	(12i)
  B11	=	- x1 a Y - x1 a Z	(Fe-I)	(12i)
  B12	=	- x1 a X - x1 a Z	(Fe-I)	(12i)
  B13	=	- x1 a X - x1 a Y	(Fe-I)	(12i)
  B14	=	½ a X	(Ni-I)	(3d)
  B15	=	½ a Y	(Ni-I)	(3d)
  B16	=	½ a Z	(Ni-I)	(3d)
  B17	=	+ ½ a X + x2 a Y + x2 a Z	(Fe-II)	(12j)
  B18	=	+ x2 a X + ½ a Y + x2 a Z	(Fe-II)	(12j)
  B19	=	+ x2 a X + x2 a Y + ½ a Z	(Fe-II)	(12j)
  B20	=	+ ½ a X + x2 a Y - x2 a Z	(Fe-II)	(12j)
  B21	=	+ x2 a X + ½ a Y - x2 a Z	(Fe-II)	(12j)
  B22	=	+ x2 a X - x2 a Y + ½ a Z	(Fe-II)	(12j)
  B23	=	+ ½ a X - x2 a Y + x2 a Z	(Fe-II)	(12j)
  B24	=	- x2 a X + ½ a Y + x2 a Z	(Fe-II)	(12j)
  B25	=	- x2 a X + x2 a Y + ½ a Z	(Fe-II)	(12j)
  B26	=	+ ½ a X - x2 a Y - x2 a Z	(Fe-II)	(12j)
  B27	=	- x2 a X + ½ a Y - x2 a Z	(Fe-II)	(12j)
  B28	=	- x2 a X - x2 a Y + ½ a Z	(Fe-II)	(12j)
  B29	=	½ a Y + ½ a Z	(Ni-II)	(3d)
  B30	=	½ a X + ½ a Z	(Ni-II)	(3d)
  B31	=	½ a X + ½ a Y	(Ni-II)	(3d)
  B32	=	½ a X + ½ a Y + ½ a Z	(Fe-III)	(1b)

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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).