Constant RATE_WINDOW_EV 

pub const RATE_WINDOW_EV: (f64, f64);

The window of the rate refinement and of the rate gate (#291, #339): E - E_F from 2 to 20 eV. The upper end covers the steep rise of the rate above the Fermi level, which for the Al single pole peaks in error at 15 to 17 eV. The lower end lies below the transport cutoff of every default δ run of validation/experiments/se_yield.py (1 eV above the vacuum level, at least 5 eV above E_F); the cutoff-band-bottom runs read the rate down to 1 eV above E_F. Below 2 eV the rate starts from zero at E_F, and a relative tolerance there would bisect towards that node without end.