Vampire has a wide range of built in particle shapes which can be used to generate different geometries and structures in the code. The structures are cut from a single bulk crystal. This tutorial explains how to generate a truncated octahedron.
Specify a truncated octahedron particle shape using
create:truncated-octahedron
Specify a particle size using
dimensions:particle-size = <size>
where size
is the size of the system in Angstroms. Remember that the unit specifier can by used to change the default unit, eg
dimensions:particle-size = 10 !nm
generates a particle 10 nm in size.
Note
To correctly cut a particle the particle dimensions should be less than the system dimensions defined by
dimensions:system-size = <size>
It is always a good idea to visually verify the generated structure by generating output viewable using rasmol or jmol. For truncated octahedrons this is essential if you want to generate a perfect structure, with equal numbers of atoms along the hexagonal and square faces, as this is not guaranteed by the code. In general the particle size must be manually adjusted to generate such a perfect structure.
Copyright R F L Evans 2013-2018