title test collisional excitation only, very high density to force H to LTE
hden = 18
no induced processes  (OK) 
hydrogen collisional ionization off 
hydrogen collisions 2s2p off 
hydrogen levels large
stop lyman optical depth -6
constant temperature = 20,000K
stop zone 1
black body, T=50,000K
ionization parameter -8
set dr 0
init file="hheonly.ini"
iterate
print departure coefficients
print h-like levels
print last iteration
assert h-like departure coef hydrogen  0.14
assert hydrogen 2 ionization -0.500
assert helium 2 ionization -1.302
punch asserts "hcexc.asr" last
c hcexc.in
