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prisms-center / CASMcode

First-principles statistical mechanical software for the study of multi-component crystalline solids
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casm enum in 2D case #343

Open sjtuzhanglei opened 10 months ago

sjtuzhanglei commented 10 months ago

When I do casm enum on only a-b plane, it could generates the weird transformation matrix. Is it a bug of the program? Should I avoid transformation matrix like this:

This puts my c lattice vector upside down: "SCEL3_3_1_1_0_0_0" : [ [ 0, 3, 0 ], [ 1, 0, 0 ], [ 0, 0, -1 ]

This swaps my c lattice vector to the new b axis:
"SCEL5_1_5_1_0_0_0" : [ [ 1, 0, 0 ], [ 0, 0, 5 ], [ 0, -1, 0 ]

Also, when I do casm init, it suggests me to use a prim.niggli.json file, but I couldn't see a difference between this and my original prim.json file.

bpuchala commented 10 months ago

casm enum always saves supercells in a CASM canonical form because it is primarily intended to only keep symmetrically unique configurations, although non-primitive configurations may also be kept as an option.

I could inspect the prim init suggestion if you're willing to share by email. CASM will suggest a Niggli cell and a particular orientation based on the same lattice canonical form method linked above so that the volume 1 supercell is simply the prim lattice x identity matrix.