basis.Expansion

Class basis.Expansion():

Stores the expansion.

The expansion consists of the integer coefficients of the reciprocal lattice vectors used in the Fourier expansion of fields, permittivities, etc. in the FMM scheme.

Args:

• basis_coefficients: The integer coefficients of the primitive reciprocal lattice vectors, which generate the full set of reciprocal-space vectors in the expansion.
• num_terms: The number of terms in the expansion.