Crystal Lattice Structures:	Creation Date: 27 Mar 2008
	Last Modified: 27 Mar 2008

The AsCuSiZr 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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• This is the prototype structure of the recently discovered superconductor La[O$_{1-x}F$_x$]FeAs. The mapping is Si → O, Cu → Fe, As → As, and La → La.
• Removing either the Copper or Silicon atoms reduces this to the Matlockite (PbFCl) structure.

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• Prototype: AsCuSiZr
• Pearson Symbol: tP8
• Strukturbericht Designation: none
• Space Group: P4/nmm (Cartesian and lattice coordinate listings available)
• Number: 129
• Reference: V. Johnson and W. Jeitschko, J. Solid State Chem 11, 161 (1974).
• Other Compounds with this Structure: LaOFeAs, AsCuHfSi, As₂CuU, Bi₂CuMn, CoLiSb₂, Cu Ge₂Hf, LaMnSb₂, NiPrSb₂
• Primitive Vectors:

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

• Basis Vectors:

  B1	=	- ¼ A1 + ¼ A2	=	- ¼ a X + ¼ a Y	(2a)	(Si)
  B2	=	+ ¼ A1 - ¼ A2	=	+ ¼ a X - ¼ a Y	(2a)	(Si)
  B3	=	- ¼ A1 + ¼ A2 + ½ A3	=	- ¼ a X + ¼ a Y + ½ c Z	(2b)	(Cu)
  B4	=	+ ¼ A1 - ¼ A2 + ½ A3	=	+ ¼ a X - ¼ a Y + ½ c Z	(2b)	(Cu)
  B5	=	+ ¼ A1 + ¼ A2 + x1 A3	=	+ ¼ a X + ¼ a Y + x1 c Z	(2c)	(As)
  B6	=	- ¼ A1 - ¼ A2 - x1 A3	=	- ¼ a X - ¼ a Y - x1 c Z	(2c)	(As)
  B7	=	+ ¼ A1 + ¼ A2 + x2 A3	=	+ ¼ a X + ¼ a Y + x2 c Z	(2c)	(Zr)
  B8	=	- ¼ A1 - ¼ A2 - x2 A3	=	- ¼ a X - ¼ a Y - x2 c Z	(2c)	(Zr)

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Structures indexed by: Strukturbericht Symbol Pearson Symbol Space Group Prototype

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