Crystal Lattice Structures:	Reference Date: 13 May 1998
	Last Modified: 21 Oct 2004

The TiSi₂ (C54) 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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• Thanks to Frances Ross of IBM for suggesting the inclusion of this structure.
• I made a mistake in the previous listing of the coordinates. If you look at Pearson's Handbook you find the position of the prototype Si atom as "(x 0 0)" where x is about 1/3. It turns out that this is the position when the origin is taken as the site of a Titanium atom. I, however, want the origin at the inversion site. This is an alternative position listed in the space group tables. In this case the prototype position for the Si atom is "(¼+x,¼,¼)". However, the two values of x are not the same. By comparing the position of Si relative to Ti, we see that we should have x_new = x_old+1/8. Thus the true value of x should be near 1/8+1/3=11/24. In the previous pictures and files I used x=1/3 anyway. This led to some Si and Ti atoms being too close (and no one noticed). Now I'm using the Pearson's Handbook "best" (i.e. newest) experimental value, 0.3365+1/8=0.4615 to generate the pictures.
• 22 March 2003: As pointed out by Dave Pankhurst, the lattice coordinates of the B₃ and B₄ basis vectors were incorrect. The vectors in LaTeX output format remain correct.

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• Prototype: TiSi₂
• Pearson Symbol: oF24
• Strukturbericht Designation: C54
• Space Group: Fddd (Cartesian and lattice coordinate listings available)
• Number: 70
• Other Elements with this Structure: TiGe₂, ZrSn₂, RuAl₂ OsGa₂, RuGa₂
• Primitive Vectors:

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

• Basis Vectors

  B1	=	+ 1/8 A1 + 1/8 A2 + 1/8 A3	=	+ 1/8 a X + 1/8 b Y + 1/8 c Z	(Ti)	(8a)
  B2	=	- 1/8 A1 - 1/8 A2 - 1/8 A3	=	- 1/8 a X - 1/8 b Y - 1/8 c Z	(Ti)	(8a)
  B3	=	+ (¼ - x) A1 + x A2 + x A3	=	+ x a X + 1/8 b Y + 1/8 c Z	(Si)	(16e)
  B4	=	- (¼ - x) A1 - x A2 - x A3	=	- x a X - 1/8 b Y - 1/8 c Z	(Si)	(16e)
  B5	=	+ x A1 + (1/4 - x) A2 + (1/4 - x) A3	=	+ (1/4 - x) a X + 1/8 b Y + 1/8 c Z	(Si)	(16e)
  B6	=	- x A1 - (1/4 - x) A2 - (1/4 - x) A3	=	- (1/4 - x) a X - 1/8 b Y - 1/8 c Z	(Si)	(16e)

See these vectors in LaTeX output format.

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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).