Double precision calculations for  scattering and absorption of light by homogeneous spherical particles can be run with fllmie.f, which will provide cross sections for extinction, total scattering, differential scattering, and absorption (determined by a separate calculation as well as from the difference of extinction and scattering). The code will also output the lidar (radar) backscattering efficiency,  the <cos> parameter, and the phase matrix.
    Calculations have been run for size parameters of up to 106, which is something like a crystal ball illuminated by a distant Na-D light source. For size parameters below 4*104 there are no problems at all. The <cos> and angle-dependent functions get clobbered by some kind of round-off error above that value, however, and I am curious to know if there is a way to avoid this without extending the code's precision. For applications to atmospheric optics, of course, nothing can attain these optical sizes and maintain its sphericity anyway, and the issue of round-off error becomes largely an academic one.
 
 

• The fulkot.f program treats a concentrically stratified sphere as a concave/convex spherical resonator.

• A program that treats a pair of spheres by the order-of-scattering technique (with a matrix inversion option) will be posted as dimer.f.

• The code inclsn.f calculates, by order-of-scattering or via a linear equation solver, the optical properties of an eccentrically stratified sphere.