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

# A Hypothetical cI32 Austenite Structure

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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 afcc = ½ a.

• 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: This is a mirror of an old page created at theNaval Research LaboratoryCenter for Computational Materials ScienceThe 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).