-expand <ex> <ey> <ez>
or
-e <ex> <ey> <ez>
This option allows to "expand" a system in the three directions of space. It can be usefull for (but not restricted to) building a supercell from a unit cell.
The translational vectors used to repeat the system are the base vectors of the original cell, noted Hx
, Hy
and Hz
. The command-line parameters must be integers and, if they need any explanation at all:
Hx
;Hy
;Hz
.Defaults are <ex> = <ey> = <ez> = 1. If you enter 0 in one or more dimensions, they will be automatically replaced by 1, as a zero dimension would wipe out the whole system.
pikashu unitcell.cfg supercell.xyz -e 2 2 4
This will create a 2x2x4 supercell from unitcell.cfg
, and output it to supercell.xyz
.
pikashu unitcell.cfg -e 2 2 4 supercell.xyz
Same as previous example. Note that the -e 2 2 4
statement cannot be broken, but intput and output file names can be specified before or after it.