Opacity API

description here.

Thomson_scattering(n_e)	Thomson scattering of free electrons (non-relativistic).
HIbf_CrossSec1(k, wl)	return bound-free cross section of a HI atom in n=k in unit of e-18 cm**2
HIbf_CrossSection(T, wl)	return bound-free cross section of a HI atom in LTE in unit of e-26 cm^2
HIff_CrossSection(T, wl)	return free-free cross section of a HI atom in LTE in unit of e-26 cm^2
Hminus_CrossSection(T, wl, n_e)	return free-free & bound-free cross section of a H-(negative hidrogen) in LTE in unit of e-26 cm^2
HIRayleigh_CrossSection(wl)	return Rayleigh scattering cross section of a HI atom in unit of e-26 cm^2
avH2p(T, wl)	H2+ opacity per 1 HI atom and per 1 H+, scaled by e26,
H2p_CrossSection(T, wl, n_e, n_H)	return H2+ CrossSection per 1 HI atom n unit of e-26 cm^2 in LTE
xclte(T, n_H, n_e, wl)	LTE continuum opacity in cm-1, incruding HI, H-, H2, rayleigh scat.