Crystal Lattice Structures: Creation Date:  3 Jul 2008 Last Modified:  3 Jul 2008

# The Orthorhombic Tridymite (SiO2) Structure

You can now

• As noted in the reference, this data is taken from meteoric SiO2.
• The z coordinates of the reference have been shifted by ¼ c so that the positions agree with the standard space group tables.

• Prototype: Orthorhombic Tridymite (SiO2)
• Pearson Symbol: oC24
• Strukturbericht Designation: None
• Space Group: C2221 (Cartesian and lattice coordinate listings available)
• Number: 20
• Reference: W. A. Dollase, Acta Cryst. 23 617 (1994).
• Primitive Vectors:  A1 = ½ a X - ½ b Y A2 = ½ a X + ½ b Y A3 = c Z
• Basis Vectors:  B1 = + x1 A1 + x1 A2 = + x1 a X (O-I) (4a) B2 = - x1 A1 - x1 A2 + ½ A3 = - x1 a X + ½ c Z (O-I) (4a) B3 = - y2 A1 + y2 A2 + ¼ A3 = + y2 b Y + ¼ c Z (O-II) (4b) B4 = + y2 A1 - y2 A2 + ¾ A3 = - y2 b Y + ¾ c Z (O-II) (4b) B5 = + (x3 - y3) A1 + (x3 + y3) A3 + z3 A3 = + x3 a X + y3 b Y + z3 c Z (O-III) (8c) B6 = - (x3 - y3) A1 - (x3 + y3) A3 + (½ + z3) A3 = - x3 a X - y3 b Y + (½ + z3) c Z (O-III) (8c) B7 = - (x3 + y3) A1 - (x3 - y3) A3 + (½ - z3) A3 = - x3 a X + y3 b Y + (½ - z3) c Z (O-III) (8c) B8 = + (x3 + y3) A1 + (x3 - y3) A3 - z3 A3 = + x3 a X - y3 b Y - z3 c Z (O-III) (8c) B9 = + (x4 - y4) A1 + (x4 + y4) A3 + z4 A3 = + x4 a X + y4 b Y + z4 c Z (Si) (8c) B10 = - (x4 - y4) A1 - (x4 + y4) A3 + (½ + z4) A3 = - x4 a X - y4 b Y + (½ + z4) c Z (Si) (8c) B11 = - (x4 + y4) A1 - (x4 - y4) A3 + (½ - z4) A3 = - x4 a X + y4 b Y + (½ - z4) c Z (Si) (8c) B12 = + (x4 + y4) A1 + (x4 - y4) A3 - z4 A3 = + x4 a X - y4 b Y - z4 c Z (Si) (8c)

Go back to the Quartz and Related Structures page.

Go back to Crystal Lattice Structure page.

 Structures indexed by: This is a mirror of an old page created at theNaval Research LaboratoryCenter for Computational Materials ScienceThe 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).