Crystal Lattice Structures:	Creation Date: 30 Mar 2001
	Last Modified: 22 Jan 2009

The βNp (A_d) 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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• When z = ½ the atoms in this structure are in the L1₀ (CuAu) or the A6 (Indium) structure.
• This structure is identical to the B10 (PbO) structure. Pearson's Handbook, along with the original papers, give the space group as P42₁. However, as noted by Structure Reports 15, 121 (1951), the correct space group is P4/nmm. P42₁ is a subgroup of P4/nmm.
• The positions here are obtained from Donohue by shifting to origin by the vector (¾ a,¼ b, 0). This places the origin at the inversion site.
• 22 Jan 2009: Fixed sign of the B₄ lattice coordinates.

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• Prototype: βNp
• Pearson Symbol: tP4
• Strukturbericht Designation: A_d
• Space Group: P4/nmm (Cartesian and lattice coordinate listings available)
• Number: 129
• Reference: Donohue, Structures of the Elements, p. 154.
• Other Compounds with this Structure: PbO, BiIn, FeSe, FeS, OSn, CuFeTe₂
• Primitive Vectors:

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

• Basis Vectors:

  B1	=	¾ A1 + ¼ A2	=	¾ a X + ¼ a Y	(Np-I)	(2a)
  B2	=	¼ A1 + ¾ A2	=	¼ a X + ¾ a Y	(Np-I)	(2a)
  B3	=	¼ A1 + ¼ A2 + z A3	=	¼ a X + ¼ a Y + z c Z	(Np-II)	(2c)
  B4	=	¾ A1 + ¾ A2 - z A3	=	¾ a X + ¾ a Y - z c Z	(Np-II)	(2c)

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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).