Crystal structure

periodictable.crystal_structure

Crystal structure data.

Adds crystal_structure to the periodic table. Each crystal structure is a dictionary which contains the key ‘symmetry’. Depending on the value of crystal_structure[‘symmetry’], one or more parameters ‘a’, ‘c/a’, ‘b/a’, ‘d’, and ‘alpha’ may be present according to the following table:

Crystal lattice parameters

Symmetry	Parameters
atom
diatom	d
BCC	a
fcc	a
hcp	c/a, a
Tetragonal	c/a, a
Cubic	a
Diamond	a
Orthorhombic	c/a, a, b/a
Rhombohedral	a, alpha
SC	a
Monoclinic

Example:

>>> import periodictable as elements
>>> print(elements.C.crystal_structure['symmetry'])
Diamond
>>> print(elements.C.crystal_structure['a'])
3.57

This data is from Ashcroft and Mermin.

periodictable.crystal_structure.init(table, reload=False)

Add crystal_structure field to the element properties.