aplowman / bravais Goto Github PK

Consider doing one initial alignment, and then rotating from that?

Arbitrary orientations would involve specifying two direction vectors. Firstly, the direction in which one of the lattice vectors should point, and secondly, the orientation of a plane in which a second lattice vector should lie?

Should be done after #9.

The Sites class can then be used more visibly in atomistic to provide common methods for things like finding which atom/lattice/interstic sites are within a bounded volume. In bravais it will be used internally.

For example, in the monoclinic case, we might want to specify the restrictions as "two of the angle parameters must be 90 degrees" as opposed to "angles alpha and beta must be 90 degrees".

Implement BravaisLattice.__eq__ method.

The following should evaluate to True, but it currently does not:

blA = BravaisLattice('cubic')
blB = BravaisLattice('cubic')
blA == blB

Specifically in the method BravaisLattice._compute_unit_cell, but also need to add alignment attribute to BravaisLattice and BravaisLattice.__init__ docstrings.

bl = BravaisLattice('cubic')
bl.row_or_column = 'row'
bl.lattice_sites

Produces:

array([[0.],
       [0.],
       [0.]])

...when it should produce:

array([[0., 0., 0.]])

Allow this to be toggled after instantiation in the same way as the row_or_column attribute. If True, angles will be reported in degrees, otherwise in radians.

At the moment, we only allow the rhombohedral centring type for the rhombohedral lattice (which is like a hexagonal unit cell with three lattice sites along the diagonal). The primitive setting would be the system that looks like a cube stretched along its diagonal.

See here.

Should be able to do:

import bravais

bravais.__version__

Got this warning regarding the BravaisLattice._validate_params method, when running on Python 3.7.2:

YAMLLoadWarning:

calling yaml.load() without Loader=... is deprecated, as the default Loader is unsafe. Please read https://msg.pyyaml.org/load for full details.

The following attributes should act like properties after initial assignment:

• lattice vector lengths: a, b, c
• lattice vector angles: alpha, beta, gamma
• lattice_system
• centring_type

At the moment, we only accept the single digit code.

P -> primitive
B -> base
I -> body
F -> face
R -> rhombohedral