Build · module 09
Crystal
Build a crystal from its space group (all 230, in their ITA settings), lattice and asymmetric unit, or import a CIF — then make supercells, find symmetry, reduce cells, cut clusters and add defects.
Open it Build›Crystal…
- You start with
- A space group with lattice and sites, a CIF, or a structure from the library.
- You get
- A periodic crystal, savable as CIF or VASP POSCAR.
Step by step
Pick the space group
Search by symbol, number or system (
Pnma,14,cubic).Set the lattice and sites
a, b, c in Å and α, β, γ in degrees. Under Asymmetric unit, Add site with label, element, x, y, z and occupancy — or Import CIF, or pick one From the library.
Use the symmetry tools
Apply symmetry, Find symmetry, Primitive cell and a supercell, with a tolerance of 0.001–0.1 Å.
Press Build crystal
The crystal opens as a new structure. Cell tools then act on it: Niggli reduction, conventional cell, redefine the lattice, a vacuum slab, a cluster, point defects or a nanowire.
Save it
File › Save as CIF (P 1 with the cell and formula; opens in VESTA, Mercury, pymatgen, ASE) or VASP POSCAR (VASP 5, atoms grouped by element).
The same without the Studio
Every Studio page calls the same core as the caps command and the caps Python package, so a step you clicked can be repeated in a script.
caps crystal --group 'P 42/m n m' --cell 4.594,4.594,2.959 \
--sites 'Ti1 Ti 0 0 0; O1 O 0.3048 0.3048 0' --supercell 2,2,2 -o rutile.cif
caps crystal rutile.cif --find-symmetryfrom caps import build
rutile = build.crystal("P 42/m n m", 4.594, 4.594, 2.959,
[("Ti1", "Ti", 0, 0, 0), ("O1", "O", 0.3048, 0.3048, 0)],
supercell=(2, 2, 2))
rutile.save("rutile.vasp")
