Cell

Cell is a set of three vectors that defines a periodic lattice in real space.

Magnopy stores it in the same way as many python codes do (spglib, Wulfric, ...).

cell is a two-dimensional \(3\times3\) matrix (array-like), that groups three lattice vectors as its rows. Here is an example of an orthorhombic cell

>>> cell = [
...     [3.5534, 0.0000, 0.0000],
...     [0.0000, 4.7449, 0.0000],
...     [0.0000, 0.0000, 8.7605],
... ]

with the three lattice vectors being

>>> cell[0] # a_1
[3.5534, 0.0, 0.0]

>>> cell[1] # a_2
[0.0, 4.7449, 0.0]

>>> cell[2] # a_3
[0.0, 0.0, 8.7605]

cell is one of the three objects that are required for creation of an instance of the SpinHamiltonian class. It is then stored as an immutable attribute SpinHamiltonian.cell.

Hint

Magnopy does not define any helper functions to manipulate with the cell, as it is out of the scope of this package. Instead we depend on Wulfric for all manipulations with the cell. For example, to compute the matrix of the cell from six lattice parameters one can use wulfric.cell.from_params() function.