title test energy conservation with vastly optically thick dust
c
c commands controlling continuum =========
black 500 STE
c
c commands for density & abundances =========
init "honly.ini"
hden 0
grains ism single graphite 
c
c commands controlling geometry  =========
stop Av 1000
sphere 
stop temperature 100K
c
c other commands for details     =========
iterate
constant temper 500 K
no grain gas collisional energy exchange
no molecules 
cosmic rays background 
c
c commands controlling output    =========
save grain temperature "grains_conserve_pp.grntem"
save overview "grains_conserve_pp.ovr"
save dr "grains_conserve_pp.dr"
save continuum units microns "grains_conserve_pp.con"
save line cumulative "grains_conserve_pp.cum"
TALL 10000A
end of line
c
c commands giving the monitors    =========
monitor grain temperature 1 500K
monitor Tu 500K error 0.02
c
c grains_conserve_pp.in
c class limit 
c ========================================
c 

This tests that multiple absorption / reemission by dust conserves energy
Energy density and grain temperatures should be exactly 500 K