QEtoolkit
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Unit-cell to primitive-cell
Upload file(Unit cell,
pw.x-input/POSCAR
)：
Choose Bravais lattice type:
1(cubic P)
2(fcc)
3(bcc)
4(hexagonal)
5(trigonal)
6(tetragonal P)
7(tetragonal body-centered)
8(orthorhombic P)
9(orthorhombic base-centered)
10(orthorhombic face-centered)
11(orthorhombic body-centered)
12(monoclinic P)
13(monoclinic base-centered)
14(triclinic)
N.B. :
1. Input unit-cell structure. If you are not sure about what kind of cell you have, go to
FindPrim
to get primitive cell. ibrav>0 is recommended for the pw.x-input of unit cell, which are ibrav=1,4,6,8,12. Otherwise, use CELL_PARAMETERS(POSCAR line 3 to 5) with the fomat satisfying v1,v2,v3 in
INPUT_PW
. Only ibrav>0 is supported for now. The transform matrix are
Table 3
.
2. Choose the type of Bravais lattice of the crystal, not the ibrav in pw.x-input file. For instance, the space group of cubic-SiC is F
4
3M（Hermann–Mauguin symbol see
ITC A ch.4.3
, No. 216), From the first letter in H-M symbol F, we can get the bravais lattice is face-centered cubic. (P for simple, I for body-centered, F for face-centered, A, B, C for base centered, H for hexagonal, R for rhombohedral). To convert the unit cell to primitive cell, upload the unit cell file with 8 atoms, choose Bravais 2, then we will get result of primitive cell with 2 atoms.