Datasets: 
 broaden_poly (int[])
If 1, Doppler broaden curve fit for window with corresponding index.
If 0, do not.
 curvefit (double[][][])
Curve fit coefficients. Indexed by (window index, coefficient index,
reaction type).
 data (complex[][])
Complex poles and residues. Each pole has a corresponding set of
residues. For example, the \(i\)th pole and corresponding residues
are stored as
\[\text{data}[:,i] = [\text{pole},~\text{residue}_1,~\text{residue}_2,
~\ldots]
\]
The residues are in the order: scattering, absorption, fission. Complex
numbers are stored by forming a type with “\(r\)” and “\(i\)”
identifiers, similar to how h5py does it.
 E_max (double)
Highest energy the windowed multipole part of the library is valid for.
 E_min (double)
Lowest energy the windowed multipole part of the library is valid for.
 spacing (double)
\[\frac{\sqrt{E_{max}}  \sqrt{E_{min}}}{n_w}
\]
Where \(E_{max}\) is the maximum energy the windows go up to.
\(E_{min}\) is the minimum energy, and \(n_w\) is the number of
windows, given by windows .
 sqrtAWR (double)
Square root of the atomic weight ratio.
 windows (int[][])
The poles to start from and end at for each window. windows[i, 0] and
windows[i, 1] are, respectively, the indexes (1based) of the first and
last pole in window i.
