Constant DENSITY_BOUNDARY 

pub const DENSITY_BOUNDARY: [[f64; 10]; 8];

Density boundary parameters per species (8 species x 10 terms).

Each row contains reference density, mixing ratio, reference altitude, correction amplitude, correction altitude, scale height, and chemistry correction parameters for one species. Species order: He, O, N2, O2, Ar, H, N, anomalous O.