Cell

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

To store it, magnopy uses the approach that is typical for many python-based codes (spglib, wulfric, ...).

cell is a two-dimensional \(3\times3\) matrix (array-like), that groups three lattice vectors. The rows of the cell are vectors, while the columns are cartesian coordinates. Here is an example of a simple 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 the SpinHamiltonian class. It is stored as an immutable attribute SpinHamiltonian.cell.