Crystal Lattice Structures:	Creation Date: 23 Jun 1997
	Last Modified: 21 Oct 2004

The bct5 Structure of Silicon

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 bct5 structure is a tetragonal analog of the diamond structure, with 5-fold coordination. It was proposed by L.L. Boyer, Efthimios Kaxiras, J.L. Feldman, J.Q. Broughton, and M.J. Mehl in Phys. Rev. Lett. 67, 715-8 (1991) as a low energy, metastable phase of silicon, based on first-principles calculations and model potentials. So far as I know, this has not been observed experimentally. A search of Pearson's Handbook does not show any compound with this structure.

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• Prototype: bct5 Si
• Pearson Symbol: tI4
• Space Group: I4/mmm (Cartesian and lattice coordinate listings available)
• Number: 139
• Reference: L. L. Boyer et al., Phys. Rev. Lett. 67, 715 (1991).
• Other Elements with this Structure: apparently none (See above)
• Primitive Vectors:

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

• Basis Vectors:

  B1	=	+ z A1 + z A2 - 2 z A3	=	- z c Z	(Si)	(4e)
  B2	=	- z A1 - z A2 + 2 z A3	=	+ z c Z	(Si)	(4e)

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).