The database file irbasis.h5 in the git repository contains data for Lambda=10, 10², 10³, 10⁴, 10⁵, 10⁶, 10⁷.

The format of the database file has been changed from v1.x to v2.x. In v2.1, the basis functions are represented in the piecewise Legendre basis. For the defition of the piecewise Legendre basis, please refer to (A.5) and (A.6) in PRB 98, 035104 (2018).

IR basis sets for different parameter sets are stored in different HDF5 groups. Each group sets must have the structure as follows:

Dataset	Type and dimensions	Description
info/Lambda	double	Dimensionless parameter .
info/dim	int	Number of basis functions and singular values (dim).
info/statistics	int	Statistics (1 for fermions and 0 for bosons).
sl	double (dim)	Singular values .
ulx/np	int	Degree of the piece-wise polynomials for (= ).
ulx/ns	int	Number of sections for x ∈ [0, 1] (= ).
ulx/data	double (dim, nus, nup+1)	Expansion coefficients in the piecewise Legendre basis
ulx/section_edges	double (nus+1)	Edges of the sections
ulx/section_edges_corr	double (nus+1)	Corrections to ulx/section_edges (higher digits)
vly/np	int	Degree of the piece-wise polynomials for (= ).
vly/ns	int	Number of sections for y ∈ [0, 1] (= ).
vly/data		Expansion coefficients in the piecewise Legendre basis
vly/section_edges	double (nvs+1)	Edges of the sections
vly/section_edges_corr	double (nvs+1)	Corrections to vly/section_edges (higher digits)