Constant AUTOMATIC_GROWTH 

const AUTOMATIC_GROWTH: f64 = _; // 5.0929581789457448f64

The largest Re(1 / (2 eta^2)) of the automatic split (resolve_split): 16 / pi from |k L| = 8 on, with a relative margin of 1e-12 for its rounding.

It sets the growth e^Re(1 / (2 eta^2)) of the Ewald parts. Only splits beyond it, the small splits:

• check the cancellation of their parts;
• take the real-space integrals of SmallSplitKambe;
• continue both parts to the complete sum (Shells);
• consider single Kambe integrals (Reduced::prefers_single).

The other splits keep their values and cost.