Crystal Lattice Structures:	Creation Date: 5 Aug 1997
	Last Modified: 21 Oct 2004

The ω (C6) Phase

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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• The omega phase can be either hexagonal or trigonal (shown here).
• The trigonal omega phase transforms into several high-symmetry structures under certain conditions:
  

  c/a	z	Lattice
  Arbitrary	0	Ideal Omega (C32)
  (3/8)½	1/6	bcc (A2)
  (3/2)½	1/6	simple cubic (Ah)
  6½	1/6	fcc (A1)
  Arbitrary	1/2	Simple Hexagonal Structure (Af)

• For more details about the omega phase and materials which form in the omega phase, see S.K. Sikka, Y.K. Vohra, and R. Chidambaram, Progress in Materials Science 27, 245-310 (1982). Most omega phase intermetallic alloys are disordered.
• Pearson's Handbook, at least, lists CdI₂ as the prototype for Strukturbericht designation C6.

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• Prototype: ω-CrTi, CdI₂
• Pearson Symbol: hP3
• Strukturbericht Designation: C6
• Space Group: P3m1 (Cartesian and lattice coordinate listings available)
• Number: 164
• Some systems which exhibit the omega phase: Ti, Zr, Hf, ZrNb, TiNb, TiV.
• Primitive Vectors:

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

• Basis Vectors:

  B1	=		0		(Cd)	(1a)
  B2	=	2/3 A1 + 1/3 A2 + (½ + z) A3	=	½ a X - 12-½ a Y + (½ + z) c Z	(I)	(2d)
  B3	=	1/3 A1 + 2/3 A2 + (½ - z) A3	=	½ a X + 12-½ a Y + (½ - z) c Z	(I)	(2d)

See these vectors in LaTeX output format.

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Structures indexed by: Strukturbericht Symbol Pearson Symbol Space Group Prototype

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