Crystal Lattice Structures:	Creation Date:  3 May 2002
	Last Modified: 21 Oct 2004

The Ni₃S₂ (D5_e) 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 can be considered as a prototype for a high concentration of ordered vacancies in the hcp structure. We get the ideal hcp atomic positions when y = 1/6 and z = 1/3, leaving a vacancy at the origin

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• Prototype: Ni₃S₂
• Pearson Symbol: hR5
• Strukturbericht Designation: D5_e
• Space Group: R32 (Cartesian and lattice coordinate listings available)
• Number: 155
• Other Compounds with this Structure: Ni₃Se₂
• Primitive Vectors:

  The rhombohedral lattice can be specified by the length of the primitive vectors, a, and the angle between them, θ, or by the lattice constants of the equivalent hexagonal lattice. In terms of a and θ we have

  a_hex = 2 a sin(½ θ)

  c_hex = a {3 [1 + 2 cos(θ)]}^½

  Pearsons' Handbook gives the lattice parameters for the hexagonal lattice. In rhombohedral form:

  A1	=	+ ½ ahex X - 12-½ ahex Y + 1/3 chex Z
  A2	=	+ 3-½ ahex Y + 1/3 chex Z
  A3	=	- ½ ahex X - 12-½ ahex Y + 1/3 chex Z

• Basis Vectors:

  Pearson's Handbook gives the coordinates of the atoms in the hexagonal unit cell. In terms of the rhombohderal cell, we have

  z_rhomb = z_hex       &       y_rhomb = x_hex - ½

  B1	=	+ z A1 + z A2 + z A3	=	+ z c Z	(2c)	(S)
  B2	=	- z A1 - z A2 - z A3	=	- z c Z	(2c)	(S)
  B3	=	½ A1 + y A2 - y A3	=	¼ (2 y + 1) a X + 48-½ (6 y - 1) a Y + 1/6 c Z	(3e)	(Ni)
  B4	=	- y A1 + ½ A2 + y A3	=	- y a X + 12-½ a Y + 1/6 c Z	(3e)	(Ni)
  B5	=	+ y A1 - y A2 + ½ A3	=	¼ (2 y - 1) a X - 48-½ (6 y + 1) a Y + 1/6 c Z	(3e)	(Ni)

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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).