triqs.lattice.utils.TB_to_sympy

triqs.lattice.utils.TB_to_sympy(TBL, analytical=True, precision=6)[source]

Return the symbolic momentum-space Hamiltonian of a tight-binding model via a Fourier-series expansion.

Parameters:

TBLTBLattice: Tight-binding lattice to convert.
analyticalbool, default True: If True, return the Hamiltonian in analytical form; if False, return it in numerical form.
precisionint, default 6: Number of digits kept in the floating-point hopping amplitudes. A smaller value can help recognise similar amplitudes, particularly for symmetric hoppings across the lattice.

Returns:

Hknumpy.ndarray: Hamiltonian of the tight-binding model in momentum space. In analytical form, the entries depend on both the k-space vector components and the lattice vectors; in numerical form, they depend only on the k-space vector components.