Mie scattering (nanoparticle extinction)

Compute scattering, absorption, and extinction efficiency factors for a nanoparticle dispersion using Mie's 1908 exact solution to Maxwell's equations. Transmittance through a filled layer via Beer-Lambert. For Kriya TiO₂, ZrO₂, SiO₂, Al₂O₃ dispersions in solvent, polymer binder, or Kriya LRI/HRI.

BHMIE algorithm (Bohren & Huffman 1983 Appendix A) with downward-recurrence logarithmic derivatives for numerical stability out to size parameter x = 100. 6 particle presets, 7 host presets (air, water, PMMA, PC, 3 Kriya binders). Four displayable spectra: Q_ext, Q_sca, Q_abs, and the Beer-Lambert transmittance through a user-sized layer at a user-chosen volume fraction. Dielectric and weakly-absorbing particles only in v1; metals (Au/Ag/Al) in v2.