[ase-users] Miller Indices for Lattice Module

[Baichuan.Sun at data61.csiro.au]

Dear ASE Users,

Currently we are using ASE.Lattice to generate crystal structures and surfaces, however we encountered 2 issues:


1.       RuntimeWarning in certain miller includes specifications
There appears to be an unhandled warning when miller indices are provided with a cross product of zero. Rather than raising an exception, ASE appears to halt the python kernel completely, stopping any further compute:

Miller Indices
[
               [1, 1, 0],
               [1, 1, 0],
               [0, 0, 1]
]

packages/ase/lattice/bravais.py:443: RuntimeWarning: divide by zero encountered in floor_divide



2.       Hexagonal Structure Miller Indices
What we are looking for is a set of miller indicies (and in fact, complete example using miller indices) that are suitable for the hexagonal crystal structure. We have attempted to create a hexagonal structure with the following specification:

Miller Indices
[
               [1, -1, 0, 0],
               [1, 0, -1, 0],
               [0, 1, -1, 0]
]

Lattice Constants
'a': 2.0
'c': 2.0

This specification yields a warning like the RuntimeWarning above. However the cross product check of the hexagonal indices above appears to be fine.

Is there a code sample available which uses miller indices in a hexagonal crystal structure?




Thanks very much!

Sincerely,
Sun

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