Crystal Lab › Prototype structures › Orthorhombic
NaP
Orthorhombic · space group P212121 (No. 19) · Pearson oP16
Symmetry elements and Wyckoff positions (interactive)
NaP in P212121
SettingUnit cell
- Lattice constants
- a = 6.038 Å, b = 5.643 Å, c = 10.142 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 345.6 ų
- Atoms in the conventional cell
- 16 (Na 8, P 8)
- Formula units Z
- 8
- Pearson symbol
- oP16 — orthorhombic, primitive lattice, 16 atoms per conventional cell
- Symmetry operations
- 4 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Na1 | Na | 4a | 4 | 0.4174 | 0.9089 | 0.0318 |
| Na2 | Na | 4a | 4 | 0.1338 | 0.6367 | 0.3313 |
| P3 | P | 4a | 4 | 0.3086 | 0.1404 | 0.2838 |
| P4 | P | 4a | 4 | 0.4287 | 0.4020 | 0.1341 |
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 16 atoms drawn above are these sites multiplied by all 4 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
AB_oP16_19_2a_2a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP16, then the space-group number 19, then the Wyckoff letters occupied by each element in turn (Na: 4a; Na: 4a; P: 4a; P: 4a). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
CsSb, KP, RbSb <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB_oP16_19_2a_2a-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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