title collisionally ionized H in LTE limit
c
c commands controlling continuum =========
black body, T = 50000 K
ionization parameter -8
c
c commands for density & abundances =========
hden = 20
set eden 20
init file="hheonly.ini"
c
c commands controlling geometry  =========
stop lyman optical depth -6
set dr -10
stop zone 1
c
c other commands for details     =========
constant temperature = 50000 K
c want pure collisional model
no induced processes  (OK) 
atom h-like collisional excitation off 
atom h-like collisions l-mixing off 
atom he-like collisional excitation off 
atom he-like collisions l-mixing off 
atom he-like collapsed levels 20
iterate
c
c commands controlling output    =========
print h-like departure coefficients
print he-like departure coefficients
print populations h-like 
print departure coefficients
save overview "limit_lte_h_t50_cion.ovr"
save performance "limit_lte_h_t50_cion.per"
save monitors last "limit_lte_h_t50_cion.asr"
c
c commands giving the monitors    =========
monitor h-like hydrogen departure coef, average 1
monitor he-like excited helium departures 1
//
c limit_lte_h_t50_cion.in
c class limit 
c ========================================
c 

This is the limiting case pure hydrogen collisional ionization,
There are no excitation or l-mixing collisions, so this tests whether 
collisional ionization - three body recombination
works in detailed balance.