Crystal Lattice Structures:	Creation Date:  5 Jun 2006
	Last Modified:  7 Nov 2007

The NbNi₈ 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
  • a = 3 a_fcc/Sqrt[2] ,
  • c = a_fcc ,
  • x_h = 1/3 , and
  • x_i = 1/3 ,
  the atoms are on the sites of the fcc lattice. The pictures here are drawn with these parameters, with a_fcc appropriate for Nickel.
• Pearson says this structure is cF36 rather than cI18, corresponding to the fact that the atoms are nearly close-packed.
• This structure is frequently used for cluster expansion models.
• 7 Nov 2007: Corrected the Pearson Symbol. It's tI18, not tI9.
• This structure is identical to the V₄Zn₅ structure. That structure should be considered the prototype.

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• Prototype: NbNi₈
• Pearson Symbol: tI18
• Strukturbericht Designation: none
• Space Group: I4/mmm (Cartesian and lattice coordinate listings available)
• Number: 139
• Reference: Pearson's Alloys pp. 343-344.
• Primitive Vectors:

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

• Basis Vectors:

  B1	=		0		(Nb)	(2a)
  B2	=	+ xh A1 + xh A2 + 2 xh A3	=	+ xh a X + xh a Y	(Ni-I)	(8h)
  B3	=	- xh A1 - xh A2 - 2 xh A3	=	- xh a X - xh a Y	(Ni-I)	(8h)
  B4	=	+ xh A1 - xh A2	=	- xh a X + xh a Y	(Ni-I)	(8h)
  B5	=	- xh A1 + xh A2	=	+ xh a X - xh a Y	(Ni-I)	(8h)
  B6	=	+ xi A2 + xi A3	=	+ xi a X	(Ni-II)	(8i)
  B7	=	- xi A2 - xi A3	=	- xi a X	(Ni-II)	(8i)
  B8	=	+ xi A1 + xi A3	=	+ xi a Y	(Ni-II)	(8i)
  B9	=	- xi A1 - xi A3	=	- xi a Y	(Ni-II)	(8i)

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Structures indexed by: Strukturbericht Symbol Pearson Symbol Space Group Prototype

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