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Crystal Lab › Prototype structures › Tetragonal

Pt₈Ti

Tetragonal · space group I4/mmm (No. 139) · Pearson tI18

Symmetry elements and Wyckoff positions (interactive)

Pt₈Ti in I4/mmm

Setting
Loading the group…
x = 0.10, y = 0.17, z = 0.08

Unit cell

Lattice constants
a = 8.312 Å, b = 8.312 Å, c = 3.897 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
269.2 ų
Atoms in the conventional cell
18 (Ti 2, Pt 16)
Formula units Z
2
Pearson symbol
tI18 — tetragonal, body-centred lattice, 18 atoms per conventional cell
Symmetry operations
32 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Ti3Ti2a20.00000.00000.0000
Pt1Pt8h80.33300.33300.0000
Pt2Pt8i80.32700.00000.0000

The multiplicity and the Wyckoff letter say how many copies of the site the group makes in one cell and on which kind of symmetry element the site sits; the 18 atoms drawn above are these sites multiplied by all 32 operations. Press Wyckoff under Colour to see the sites, and tick a symmetry element on the left to see which atoms lie on it.

How to read the label

A8B_tI18_139_hi_a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI18, then the space-group number 139, then the Wyckoff letters occupied by each element in turn (Ti: 2a; Pt: 8h; Pt: 8i). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Ni₈Mo, Ni₈Nb, Ni₈Ta, Ni₈V, Pd₈Mo, Pd₈V, Pd₈W, Pt₈Ce, Pt₈Ti, Pt₈V, Pt₈Zr <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A8B_tI18_139_hi_a-001 (M. J. Mehl et al., Comput. Mater. Sci. 136, S1 (2017); D. Hicks et al., ibid. 161, S1 (2019) and 199, 110450 (2021); S. Eckert et al., ibid. 240, 112988 (2024)). Symmetry elements, Wyckoff assignment and the diagram are computed on this page from the group operations.

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