Crystal Lattice Structures:	Reference Date: 20 Dec 1995
	Last Modified: 21 Oct 2004

The NiAs (B8₁) 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.
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• Note that the stacking is ABACABAC, with the Ni atoms on the A sites and As on B and C. The environment of the Ni atoms is fcc-like, and the environment of the As atoms is hcp-like.
• Westbrook and Fleischer give this as P6₃mmc, which we assume to mean P6₃/mmc (#194). Thus the atoms are on the same sites as the atoms in the αLa (A3') structure.
• We previously listed this structure in space group P6₃mc (#186), but that is not supported by the literature.

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• Prototype: NiAs
• Pearson Symbol: hP4
• Strukturbericht Designation: B8₁
• Space Group: P6₃/mmc (Cartesian and lattice coordinate listings available).
• Number: 194
• Reference: Pearson, Alloys, p. 452.
• Other Compounds with this Structure: AuSn, CoTe, CrSe, CuSn, FeS, IrS, MnAs, NiSn, PdSb, PtB, RhSn, VP, ZrTe
• Primitive Vectors:

  A1	=	½ a X - ½ 3½ a Y
  A2	=	½ a X + ½ 3½ a Y
  A3	=	c Z

• Basis Vectors:

  B1	=		0		(2a)	(Ni)
  B2	=	½ A3	=	½ c Z	(2a)	(Ni)
  B3	=	1/3 A1 + 2/3 A2 + ¼ A3	=	½ a X + 12-½ a Y + ¼ c Z	(2c)	(As)
  B4	=	2/3 A1 + 1/3 A2 + ¾ A3	=	½ a X - 12-½ a Y + ¾ c Z	(2c)	(As)

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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).