title constant gas pressure orion into pdr
// >>chng 00 oct 13, from 50 to 10
stop temperature 10 linear
c
c print lots of faint CO lines
print line faint -6
print lines column
print lines sort wavelength 
// >>chng 02 dec 21, change to set thickness, with new hmole
// co hits asymptote at 0.9 and so does not stop due to co
// >>chng 03 sep 12, co network cleaned up, reset thickness to
// 1 parsec, roughly the width of the cloud
// stop thickness 1 linear parsec 
// >>chng 05 dec 19, stop at AV 10000 to prevent H2-> H0 in deep regions
// due to low grain temperature - see further comments below
stop AV 1000 point
// >>chng 01 dec 30, make constant gas pressure to avoid Lya rad pressure
constant gas pressure 
// >>chng 05 jan 06, rm the itertate since this sim is soooo slooooow
// iterate
// >>chng 03 sep 12, add this command
double // mimic existence of unmodeled molecular gas
sphere 
c
c the incident continuum is two parts
c star and flux of photons striking it
// >>chng 03 sep 12, now go deep into omc1 and cannot assume plane par geometry
table read "star_kurucz_39600.dat"
c 
Q(H) 49
radius 17.4507
//
c plus hot brems 
brems 6
phi(h) 10
c
// >>chng 03 apr 30, add cosmic rays to model
c add cosmic rays, which are important at depth
cosmic rays, background
c
c we have a spherical geometry but want to simulate observing
c through a spectrometer's slit.  use the aperture
c command for this
aperture beam 
c 
c the observed microturbulence 
turbulence 8 km/sec no pressure 
c
c density and abundances
hden 4
init file="ism.ini"
abundances hii region no grains
grains orion 
// turn on PAHs with default abundance, depending on physical conditions
grains pah 
atom h2  
c
set nend 2000 
c
save performance "h2_orion_hii_pdr.per"
save overview last "h2_orion_hii_pdr.ovr"
save hydrogen 21 cm last "h2_orion_hii_pdr.21cm"
save heating "h2_orion_hii_pdr.het"
save cooling "h2_orion_hii_pdr.col"
save dr last "h2_orion_hii_pdr.dr"
save results last "h2_orion_hii_pdr.rlt"
save continuum last "h2_orion_hii_pdr.con" units microns
save hydrogen lya last "h2_orion_hii_pdr.lya" 
save grain charge last "h2_orion_hii_pdr.grnchr" 
save grain potential last "h2_orion_hii_pdr.grnpot" 
save H2 lines last "h2_orion_hii_pdr.h2lin" 
save H2 column density last "h2_orion_hii_pdr.h2col" 
save chemistry rates destruction "h2_orion_hii_pdr.H2d" "H2"
save chemistry rates creation "h2_orion_hii_pdr.H2c" "H2"
save molecules "h2_orion_hii_pdr.mol" 
save monitors "h2_orion_hii_pdr.asr" 
c
//
// >>chng 04 mar 26, add large H2
// all lines changed, so removed history
//
// >>chng 07 dec 05, from 0.656 to 0.676, RP iso updates
// >>chng 13 feb 02, from 0.676 to 0.6551, BUGFIX, largely undo r6703
monitor line luminosity "h  1" 4861 0.6551
//
// >>chng 09 feb 23, from 1.236 to 1.256, remove otslin, otscon dampers (PR #84, r2758)
// >>chng 11 jul 12, from 1.256 to 1.279, enable fit to Badnell DR suppression
// >>chng 13 feb 02, from 1.279 to 1.259, BUGFIX, largely undo r6703
monitor line luminositry "o  3" 5007 1.259
//
// >>chng 06 nov 29, from -1.115 to -1.126, Badnell DR
// >>chng 11 jul 12, from -1.126 to -1.101, enable fit to Badnell DR suppression
monitor line luminosity "totl" 4363 -1.101
//
// >>chng 06 nov 29, from 0.013 to 0.0462, Badnell DR
// >>chng 11 jul 12, from 0.0462 to 0.0759, enable fit to Badnell DR suppression
// >>chng 13 feb 02, from 0.0759 to 0.0502, BUGFIX, largely undo r6703
monitor line luminosity "o  3" 51.80m 0.0502
//
// >>chng 06 aub 06, update O+2 & N+2 CT, from 0.752 to 0.777
// >>chng 06 nov 29, from 0.777 to 0.736, Badnell DR
// >>chng 11 jul 12, from 0.736 to 0.7011, enable fit to Badnell DR suppression
// >>chng 13 feb 02, from 0.7011 to 0.7433, BUGFIX, largely undo r6703
monitor line luminosity "totl" 3727 0.7433
//
// >>chng 06 aub 06, update O+2 & N+2 CT, from -0.020 to -0.034
// >>chng 06 aug 17, from -0.034 to 0.0328, update [OII] cs
// >>chng 06 nov 29, from 0.0328 to -0.009, Badnell DR
// >>chng 10 feb 14, from -0.009 to -0.0809, update O atomic data
// >>chng 11 jul 12, from -0.0809 to -0.1305, enable fit to Badnell DR suppression
// >>chng 13 feb 02, from -0.1305 to -0.0872, BUGFIX, largely undo r6703
monitor line luminosity "totl" 7325 -0.0872
//
// >>chng 06 oct 02, from -1.678 to -1.579 HM update OI cs to Barklem '06
monitor line luminosity "o  1" 6300 -1.579 
//
// >>chng 05 jul 17, from 0.219 to 0.28 first run in 6 mo
// >>chng 12 jan 06, from 0.28 to 0.207, several H2 model changes
monitor line luminosity "o  1" 63.17m  0.207 error 0.1 
//
// >>chng 05 jul 17, from -1.10 to -1.05 first run in 6 mo
// >>chng 06 jun 02, from -1.05 to -1.09, NA refactor chem, bug fix
// >>chng 12 jan 06, from -1.09 to -1.14, several H2 model changes
monitor line luminosity "c  2" 157.6m -1.14 error 0.1 
//
// >>chng 05 jul 17, from -0.74 to -0.67 first run in 6 mo
// >>chng 12 jan 06, from -0.67 to -0.7437, several H2 model changes
monitor line luminosity "si 2" 34.81m -0.7437 error 0.1
//
// >>chng 05 dec 19, from 3.630 to 3.514, stop AV 1000
// >>chng 10 jun 22, from 3.514 to 3.534, fix botches after dBaseLines cooling/heating changes
monitor line luminosity "GraT" 0 3.534
//
// >>chng 05 sep 08, from 25.49 to 25.45, first run in two months
// >>chng 05 dec 19, from 25.45 to 23.95, stop AV 1000
monitor H2 column density 23.95 error 0.1
//
// >>chng 05 jul 17, from 22.26 to 21.89 first run in 6 mo
// >>chng 05 dec 19, from 21.89 to 20.73, stop AV 1000
monitor CO column density 20.73 error 0.15
// 
// >>chng 11 jul 16, add these
// >>chng 11 jul 16, from 10 to 12.81, add column density monitors
// >>chng 12 apr 09, from 12.81 to 13.7, update backbround CR to Indiolo_07 (8x larger)
monitor column density H3+  13.7 error 0.1
// >>chng 11 jul 16, from 10 to 10.72, add column density monitors
// >>chng 12 apr 09, from 10.72 to 10.96, update backbround CR to Indiolo_07 (8x larger)
monitor column density H2+  10.96 error 0.1
// >>chng 11 jul 16, from 10 to 11.92, add column density monitors
// >>chng 12 jan 06, from 11.92 to 11.85, several H2 model changes
monitor column density H-   11.85 error 0.1
// >>chng 11 jul 16, from 10 to 23.95, add column density monitors
monitor column density H2g  23.95 error 0.1
// >>chng 11 jul 16, from 10 to 17.2, add column density monitors
// >>chng 11 nov 16, from 17.2 to 17.07, adjust newmole monitors
// >>chng 12 jan 06, from 17.07 to 16.98, several H2 model changes
// >>chng 12 apr 09, from 16.98 to 17.03, update backbround CR to Indiolo_07 (8x larger)
monitor column density H2*  17.03 error 0.1
// >>chng 11 jul 16, from 10 to 10.94, add column density monitors
// >>chng 11 nov 16, from 10.94 to 10.88, adjust newmole monitors
monitor column density HeH+ 10.88 error 0.1
// >>chng 11 jul 16, from 10 to 16.97, add column density monitors
// >>chng 11 nov 16, from 16.97 to 16.85, adjust newmole monitors
// >>chng 12 jan 06, from 16.85 to 16.94, several H2 model changes
monitor column density O2   16.94 error 0.1
// >>chng 11 jul 16, from 10 to 16.5, add column density monitors
// >>chng 11 nov 16, from 16.5 to 16.43, adjust newmole monitors
// >>chng 12 jan 06, from 16.43 to 16.54, several H2 model changes
// >>chng 12 apr 09, from 16.54 to 16.49, update backbround CR to Indiolo_07 (8x larger)
monitor column density H2O  16.49 error 0.1
// >>chng 11 jul 16, from 10 to 15.76, add column density monitors
// >>chng 11 nov 16, from 15.76 to 15.82, adjust newmole monitors
monitor column density C2   15.82 error 0.1
// >>chng 11 jul 16, from 10 to 14.06, add column density monitors
// >>chng 11 nov 16, from 14.06 to 14.11, adjust newmole monitors
// >>chng 12 jan 06, from 14.11 to 13.9, several H2 model changes
// >>chng 13 feb 02, from 13.9 to 13.85, BUGFIX, largely undo r6703
monitor column density C3   13.85 error 0.1
// >>chng 11 jul 16, from 10 to 17.35, add column density monitors
// >>chng 11 nov 16, from 17.35 to 17.42, adjust newmole monitors
// >>chng 12 apr 09, from 17.42 to 17.74, update backbround CR to Indiolo_07 (8x larger)
monitor column density SiO  17.74 error 0.1
// >>chng 11 jul 16, from 10 to 14.17, add column density monitors
// >>chng 11 nov 16, from 14.17 to 14.12, adjust newmole monitors
// >>chng 12 apr 09, from 14.12 to 14.89, update backbround CR to Indiolo_07 (8x larger)
monitor column density OH   14.89 error 0.1
// >>chng 11 jul 16, from 10 to 13.97, add column density monitors
// >>chng 11 nov 16, from 13.97 to 14.02, adjust newmole monitors
// >>chng 12 jan 06, from 14.02 to 13.96, several H2 model changes
// >>chng 12 apr 09, from 13.96 to 14.15, update backbround CR to Indiolo_07 (8x larger)
monitor column density CN   14.15 error 0.1
// >>chng 11 jul 16, from 10 to 15.73, add column density monitors
// >>chng 11 nov 16, from 15.73 to 15.78, adjust newmole monitors
// >>chng 13 feb 02, from 15.78 to 15.84, BUGFIX, largely undo r6703
monitor column density CH   15.84 error 0.1
//
// >>chng 05 sep 08, from -2.96 to -2.93, first run in two months
// >>chng 05 dec 19, from -2.93 to -2.99, stop AV 1000
// >>chng 06 mar 02, from -2.99 to -2.94, NA Fe0, Mg0, <-> Si+, S+, C+ ct,
// also energy barrier for H + (CH and CH2) reactions
// >>chng 06 jun 02, from -2.94 to -2.84, NA refactor chem, bug fix
// >>chng 10 mar 03, from -2.84 to -2.124, fix botches after CO changes
// >>chng 10 jun 22, from -2.124 to -2.408, fix botches after dBaseLines cooling/heating changes
// >>chng 11 nov 16, from -2.408 to -2.367, adjust newmole monitors
monitor line luminosity "CO  " 650.1m  -2.367 error 0.1
//
// >>chng 05 jul 17, from -2.70 to -2.67 first run in 6 mo
// >>chng 05 dec 19, from -2.67 to -2.71, stop AV 1000
// >>chng 06 mar 02, from -2.71 to -2.66, NA Fe0, Mg0, <-> Si+, S+, C+ ct,
// also energy barrier for H + (CH and CH2) reactions
// >>chng 06 jun 02, from -2.66 to -2.56, NA refactor chem, bug fix
// >>chng 10 mar 03, from -2.56 to -1.864, fix botches after CO changes
// >>chng 10 jun 22, from -1.864 to -2.175, fix botches after dBaseLines cooling/heating changes
// >>chng 11 nov 16, from -2.175 to -2.128, adjust newmole monitors
// >>chng 12 jan 06, from -2.128 to -2.171, several H2 model changes
monitor line luminosity "CO  " 520.1m  -2.171 error 0.1
//
// >>chng 05 jul 17, from -2.50 to -2.46 first run in 6 mo
// >>chng 06 jun 02, from -2.46 to -2.35, NA refactor chem, bug fix
// >>chng 10 mar 03, from -2.35 to -1.672, fix botches after CO changes
// >>chng 10 jun 22, from -1.672 to -2.012, fix botches after dBaseLines cooling/heating changes
// >>chng 11 nov 16, from -2.012 to -1.964, adjust newmole monitors
// >>chng 12 jan 06, from -1.964 to -2.013, several H2 model changes
monitor line luminosity "CO  " 433.4m  -2.013 error 0.1
//
// >>chng 05 jul 17, from -2.33 to -2.29 first run in 6 mo
// >>chng 06 jun 02, from -2.29 to -2.21, NA refactor chem, bug fix
// >>chng 10 mar 03, from -2.21 to -1.534, fix botches after CO changes
// >>chng 10 jun 22, from -1.534 to -1.904, fix botches after dBaseLines cooling/heating changes
// >>chng 11 nov 16, from -1.904 to -1.856, adjust newmole monitors
// >>chng 12 jan 06, from -1.856 to -1.909, several H2 model changes
monitor line luminosity "CO  " 371.5m  -1.909 error 0.1
//
// >>chng 05 jul 17, from -2.18 to -2.15 first run in 6 mo
// >>chng 06 jun 02, from -2.15 to -2.10, NA refactor chem, bug fix
// >>chng 10 mar 03, from -2.1 to -1.442, fix botches after CO changes
// >>chng 10 jun 22, from -1.442 to -1.842, fix botches after dBaseLines cooling/heating changes
// >>chng 11 nov 16, from -1.842 to -1.801, adjust newmole monitors
// >>chng 12 jan 06, from -1.801 to -1.85, several H2 model changes
monitor line luminosity "CO  " 325.1m  -1.85 error 0.1
//
// >>chng 05 jul 17, from -2.06 to -2.03 first run in 6 mo
// >>chng 05 dec 19, from -2.02 to -2.07, stop AV 1000
// >>chng 06 jun 02, from -2.07 to -2.02, NA refactor chem, bug fix
// >>chng 10 mar 03, from -2.02 to -1.393, fix botches after CO changes
// >>chng 10 mar 05, from -1.393 to -1.438, update results after r3848 chng atomic data
// >>chng 10 jun 22, from -1.438 to -1.829, fix botches after dBaseLines cooling/heating changes
monitor line luminosity "CO  " 289.0m  -1.829 error 0.1
//
// >>chng 05 jul 17, from -1.99 to -1.96 first run in 6 mo
// >>chng 05 dec 19, from -1.96 to -2.00, stop AV 1000
// >>chng 09 may 12, from -2 to -1.959, H2 - H2 collision update to Lee et al 2008
// >>chng 10 mar 03, from -1.959 to -1.391, fix botches after CO changes
// >>chng 10 mar 05, from -1.391 to -1.453, update results after r3848 chng atomic data
// >>chng 10 jun 22, from -1.453 to -1.887, fix botches after dBaseLines cooling/heating changes
monitor line luminosity "CO  " 260.2m  -1.887 error 0.1
//
// >>chng 05 jul 17, from -2.00 to -1.96 first run in 6 mo
// >>chng 05 sep 08, from -1.96 to -1.92, first run in two months
// >>chng 05 dec 19, from -1.92 to -1.99, stop AV 1000
// >>chng 10 mar 03, from -1.99 to -1.445, fix botches after CO changes
// >>chng 10 mar 05, from -1.445 to -1.534, update results after r3848 chng atomic data
// >>chng 10 jun 22, from -1.534 to -2.07, fix botches after dBaseLines cooling/heating changes
monitor line luminosity "CO  " 236.5m  -2.07 error 0.1
//
// >>chng 05 jul 17, from -2.19 to -2.06 first run in 6 mo
// >>chng 05 sep 08, from -2.06 to -1.98, first run in two months
// >>chng 05 dec 19, from -1.98 to -2.12, stop AV 1000
// >>chng 07 feb 06, bugfix in r828, from -2.12 to -2.09 (9.03)
// >>chng 10 mar 03, from -2.09 to -1.578, fix botches after CO changes
// >>chng 10 mar 05, from -1.578 to -1.716, update results after r3848 chng atomic data
// >>chng 10 jun 22, from -1.716 to -2.48, fix botches after dBaseLines cooling/heating changes
monitor line luminosity "CO  " 216.9m  -2.48 error 0.1
//
// >>chng 05 dec 19, from 1600 to 1400, stop AV 1000
// >>chng 08 dec 08, from 1400 to 1266, upper limit -> equals (r2515)
// >>chng 09 jan 16, from 1266 to 1269, average of 9 runs
// >>chng 09 oct 05, from 1269 to 1255, [NI] pumping changes
// >>chng 09 nov 03, from 1255 to 1268, drift?
// >>chng 12 apr 09, from 1268 to 1194, update backbround CR to Indiolo_07 (8x larger)
monitor nzone 1194
//
// >>chng 04 dec 08, from 13 to 19 co-ion feedback, check converg
// >>chng 05 jul 17, from 19 to 25 first run in 6 mo
// >>chng 08 dec 08, from 25 to 20.36, upper limit -> equals (r2515)
// >>chng 08 dec 13, from 20.36 to 34.55, merging newsolvers branch
// >>chng 09 jan 16, from 34.55 to 34.79, average of 9 runs
// >>chng 09 feb 10, from 34.79 to 35.5, combined effect of r2655, r2669
// >>chng 09 may 30, from 35.5 to 35.0, drift down
// >>chng 11 nov 16, from 36 to 54.97, adjust newmole monitors
// >>chng 12 jan 06, from 54.97 to 30.55, several H2 model changes
monitor itrzn 30.55
//
// these added 05 jan 23
// >>chng 05 sep 08, from 25.49 to 25.45, first run in two months
// >>chng 05 dec 19, from 25.45 to 23.91, stop AV 1000
monitor H2 column density level 0  0  23.91 error 0.1
//
// >>chng 05 jul 17, from 23.34 to 23.49 first run in 6 mo
// >>chng 05 sep 08, from 23.49 to 23.55, first run in two months
// >>chng 05 dec 19, from 23.55 to 22.96, stop AV 1000
// >>chng 08 feb 10, from 22.96 to 23.03, chng CR heat efficiency
// >>chng 10 mar 03, from 23.03 to 23.13, fix botches after CO changes
// >>chng 10 mar 05, from 23.13 to 23.03, update results after r3848 chng atomic data
// >>chng 10 jun 22, from 23.03 to 22.74, fix botches after dBaseLines cooling/heating changes
// >>chng 12 aug 21, from 22.74 to 22.82, fix CRPHOT botches and HD crash
monitor H2 column density level 0  1  22.82 error 0.1
//
// >>chng 05 jul 17, from 18.74 to 19.76 first run in 6 mo
// >>chng 05 sep 08, from 19.76 to 19.81, first run in two months
// >>chng 05 dec 19, from 19.81 to 19.67, stop AV 1000
// >>chng 06 jun 02, from 19.67 to 19.50, NA refactor chem, bug fix
// >>chng 07 dec 05, from 19.50 to 19.57 H-H2 coll update
// >>chng 08 mar 17, from 19.57 to 19.52 line overlap??, not run recently
// >>chng 08 sep 25, from 19.52 to 19.56, remove damper on line pump (r2367)
// >>chng 09 may 12, from 19.56 to 19.62, H2 - H2 collision update to Lee et al 2008
// >>chng 10 mar 03, from 19.62 to 19.76, fix botches after CO changes
// >>chng 10 mar 05, from 19.76 to 19.66, update results after r3848 chng atomic data
// >>chng 10 jun 22, from 19.66 to 19.52, fix botches after dBaseLines cooling/heating changes
// >>chng 11 apr 21, from 19.52 to 19.45, fix botches due to factor of 2 in r4946
// >>chng 12 jan 06, from 19.45 to 19.19, several H2 model changes
// >>chng 12 jul 31, from 19.19 to 19.09, improve H2 LTE approach
monitor H2 column density level 0  2  19.09 error 0.1
//
// >>chng 05 jul 17, from 18.41 to 18.83 first run in 6 mo
// >>chng 05 sep 08, from 18.83 to 18.75, first run in two months
// >>chng 05 sep 17, from 18.75 to 18.71, update H- rate
// >>chng 06 mar 02, from 18.71 to 18.88, NA Fe0, Mg0, <-> Si+, S+, C+ ct,
// also energy barrier for H + (CH and CH2) reactions
// >>chng 06 jun 02, from 18.88 to 18.50, NA refactor chem, bug fix
// >>chng 07 feb 06, bugfix in r828, from 18.50 to 18.53 (9.03)
// >>chng 07 dec 05, from 18.53 to 18.83 H-H2 coll update
// >>chng 08 mar 17, from 18.83 to 18.73 line overlap??, not run recently
// >>chng 08 sep 25, from 18.73 to 18.79, remove damper on line pump (r2367)
// >>chng 09 may 12, from 18.79 to 18.85, H2 - H2 collision update to Lee et al 2008
// >>chng 11 apr 21, from 18.85 to 18.74, fix botches due to factor of 2 in r4946
// >>chng 11 nov 16, from 18.74 to 18.43, adjust newmole monitors
// >>chng 12 jan 06, from 18.43 to 17.73, several H2 model changes
// >>chng 12 jul 31, from 17.73 to 17.82, improve H2 LTE approach
// >>chng 13 feb 02, from 17.82 to 17.87, BUGFIX, largely undo r6703
monitor H2 column density level 0  3  17.87 error 0.1
//
// >>chng 05 feb 12, from 15.54 to 15.58, better H2 conv
// >>chng 05 jul 17, from 15.58 to 16.44 first run in 6 mo
// >>chng 05 sep 08, from 16.44 to 16.37, first run in two months
// >>chng 05 sep 17, from 16.37 to 16.32, update H- rate
// >>chng 06 mar 02, from 16.32 to 16.40, NA Fe0, Mg0, <-> Si+, S+, C+ ct,
// also energy barrier for H + (CH and CH2) reactions
// >>chng 06 jun 02, from 16.40 to 16.23, NA refactor chem, bug fix
// >>chng 07 dec 05, from 16.23 to 16.43 H-H2 coll update
// >>chng 07 dec 31, from 16.43 to 16.52 additional vJ H-H2 rates
// >>chng 08 mar 17, from 16.52 to 16.35 line overlap??, not run recently
// >>chng 08 sep 25, from 16.35 to 16.4, remove damper on line pump (r2367)
// >>chng 09 may 12, from 16.4 to 16.49, H2 - H2 collision update to Lee et al 2008
// >>chng 11 apr 21, from 16.49 to 16.4, fix botches due to factor of 2 in r4946
// >>chng 11 nov 16, from 16.4 to 17.17, adjust newmole monitors
// >>chng 12 jan 06, from 17.17 to 16.19, several H2 model changes
// >>chng 12 apr 09, from 16.19 to 16.26, update backbround CR to Indiolo_07 (8x larger)
monitor H2 column density level 0  4  16.26 error 0.1
//
// >>chng 05 jul 17, from 17.29 to 17.18 first run in 6 mo
// >>chng 05 sep 08, from 17.18 to 17.14, first run in two months
// >>chng 06 nov 29, from 17.14 to 17.09, Badnell DR
// >>chng 07 dec 05, from 17.09 to 16.88 H-H2 coll update
// >>chng 07 dec 31, from 16.88 to 17.11 additional vJ H-H2 rates
// >>chng 11 nov 16, from 17.11 to 17.6, adjust newmole monitors
// >>chng 12 jan 06, from 17.6 to 16.89, several H2 model changes
// >>chng 12 apr 09, from 16.89 to 16.93, update backbround CR to Indiolo_07 (8x larger)
monitor H2 column density level 0  5  16.93 error 0.1
//
// >>chng 05 feb 12, from 16.01 to 16.06, better H2 conv
// >>chng 05 jul 17, from 16.06 to 16.72 first run in 6 mo
// >>chng 05 sep 17, from 16.72 to 16.68, update H- rate
// >>chng 05 dec 19, from 16.68 to 16.55, stop AV 1000
// >>chng 06 mar 02, from 16.55 to 16.59, NA Fe0, Mg0, <-> Si+, S+, C+ ct,
// also energy barrier for H + (CH and CH2) reactions
// >>chng 06 jun 02, from 16.59 to 16.53, NA refactor chem, bug fix
// >>chng 07 apr 10, from 16.53 to 16.48, ORNL H2-He collisions
// >>chng 07 dec 05, from 16.48 to 16.40 H-H2 coll update
// >>chng 08 sep 25, from 16.4 to 16.35, remove damper on line pump (r2367)
// >>chng 09 may 12, from 16.35 to 16.25, H2 - H2 collision update to Lee et al 2008
// >>chng 11 nov 16, from 16.25 to 17.42, adjust newmole monitors
// >>chng 12 jan 06, from 17.42 to 16.32, several H2 model changes
// >>chng 12 apr 09, from 16.32 to 16.42, update backbround CR to Indiolo_07 (8x larger)
monitor H2 column density level 0  6  16.42 error 0.1
//
// >>chng 05 feb 12, from 17.29 to 17.24, better H2 conv
// >>chng 05 jul 17, from 17.24 to 17.12 first run in 6 mo
// >>chng 05 dec 19, from 17.12 to 17.03, stop AV 1000
// >>chng 07 dec 05, from 17.03 to 16.35 H-H2 coll update
// >>chng 07 dec 31, from 16.35 to 16.86 additional vJ H-H2 rates
// >>chng 11 nov 16, from 16.86 to 17.52, adjust newmole monitors
// >>chng 12 jan 06, from 17.52 to 16.61, several H2 model changes
// >>chng 12 apr 09, from 16.61 to 16.71, update backbround CR to Indiolo_07 (8x larger)
monitor H2 column density level 0  7  16.71 error 0.15
//
// >>chng 05 feb 12, from 15.52 to 15.55, better H2 conv
// >>chng 05 jul 17, from 15.55 to 16.13 first run in 6 mo
// >>chng 05 dec 19, from 16.13 to 15.94, stop AV 1000
// >>chng 07 feb 03, from 15.94 to 15.90, drift down
// >>chng 07 feb 06, bugfix in r828, from 15.99 to 15.90 (9.03)
// >>chng 07 dec 05, from 15.90 to 15.61 H-H2 coll update
// >>chng 07 dec 31, from 15.61 to 15.79 additional vJ H-H2 rates
// >>chng 08 may 16, from 15.79 to 15.785, increase error, sensitive to computational detail
// >>chng 09 may 12, from 15.79 to 15.71, H2 - H2 collision update to Lee et al 2008
// >>chng 11 nov 16, from 15.71 to 16.67, adjust newmole monitors
// >>chng 12 jan 06, from 16.67 to 15.61, several H2 model changes
// >>chng 12 apr 09, from 15.61 to 15.72, update backbround CR to Indiolo_07 (8x larger)
monitor H2 column density level 0  8  15.72 error 0.15
//
// >>chng 05 jul 17, from 16.74 to 16.62 first run in 6 mo
// >>chng 05 dec 19, from 16.62 to 16.53, stop AV 1000
// >>chng 07 dec 05, from 16.53 to 15.50 H-H2 coll update
// >>chng 07 dec 31, from 15.50 to 16.33 additional vJ H-H2 rates
// >>chng 11 nov 16, from 16.33 to 16.94, adjust newmole monitors
// >>chng 12 jan 06, from 16.94 to 15.82, several H2 model changes
// >>chng 12 apr 09, from 15.82 to 15.96, update backbround CR to Indiolo_07 (8x larger)
monitor H2 column density level 0  9  15.96 error 0.15
//
// >>chng 05 feb 12, from 14.54 to 14.57, better H2 conv
// >>chng 05 jul 17, from 14.57 to 15.15 first run in 6 mo
// >>chng 05 sep 08, from 15.15 to 15.07, first run in two months
// >>chng 05 dec 19, from 15.07 to 14.93, stop AV 1000
// >>chng 07 feb 06, bugfix in r828, from 14.93 to 14.89 (9.03)
// >>chng 07 dec 31, from 14.89 to 14.94 additional vJ H-H2 rates
// >>chng 08 feb 10, from 14.94 to 14.99, chng CR heat efficiency
// >>chng 08 mar 17, from 14.99 to 14.92 line overlap??, not run recently
// >>chng 11 nov 16, from 14.92 to 15.86, adjust newmole monitors
// >>chng 12 jan 06, from 15.86 to 14.82, several H2 model changes
// >>chng 12 apr 09, from 14.82 to 15.12, update backbround CR to Indiolo_07 (8x larger)
monitor H2 column density level 1  0  15.12 error 0.1
//
// >>chng 05 jul 17, from 15.97 to 15.86 first run in 6 mo
// >>chng 05 sep 08, from 15.86 to 15.78, first run in two months
// >>chng 05 dec 19, from 15.78 to 15.74, stop AV 1000
// >>chng 06 mar 02, from 15.74 to 15.78, NA Fe0, Mg0, <-> Si+, S+, C+ ct,
// also energy barrier for H + (CH and CH2) reactions
// >>chng 06 jun 02, from 15.78 to 15.71, NA refactor chem, bug fix
// >>chng 07 apr 10, from 15.71 to 15.76, ORNL H2-He collisions
// >>chng 07 dec 05, from 15.76 to 15.94 H-H2 coll update
// >>chng 07 dec 31, from 15.94 to 15.70 additional vJ H-H2 rates
// >>chng 09 may 12, from 15.7 to 15.63, H2 - H2 collision update to Lee et al 2008
// >>chng 11 nov 16, from 15.63 to 15.98, adjust newmole monitors
// >>chng 12 jan 06, from 15.98 to 15.38, several H2 model changes
// >>chng 12 apr 09, from 15.38 to 15.46, update backbround CR to Indiolo_07 (8x larger)
monitor H2 column density level 1  1  15.46 error 0.1
//
// >>chng 05 feb 12, from 14.85 to 14.87, better H2 conv
// >>chng 05 jul 17, from 14.87 to 15.34 first run in 6 mo
// >>chng 05 sep 08, from 15.34 to 15.23, first run in two months
// >>chng 05 dec 19, from 15.23 to 15.19, stop AV 1000
// >>chng 07 dec 05, from 15.19 to 15.11 H-H2 coll update
// >>chng 07 dec 31, from 15.11 to 15.15 additional vJ H-H2 rates
// >>chng 08 mar 17, from 15.15 to 15.11 line overlap??, not run recently
// >>chng 09 may 12, from 15.11 to 15.21, H2 - H2 collision update to Lee et al 2008
// >>chng 11 nov 16, from 15.21 to 16.12, adjust newmole monitors
// >>chng 12 jan 06, from 16.12 to 15.18, several H2 model changes
// >>chng 12 apr 09, from 15.18 to 15.44, update backbround CR to Indiolo_07 (8x larger)
monitor H2 column density level 1  2  15.44 error 0.1
//
// >>chng 05 jul 17, from 15.69 to 15.62 first run in 6 mo
// >>chng 05 sep 08, from 15.62 to 15.55, first run in two months
// >>chng 07 apr 10, from 15.55 to 15.49, ORNL H2-He collisions
// >>chng 07 dec 05, from 15.49 to 15.59 H-H2 coll update
// >>chng 07 dec 31, from 15.59 to 15.44 additional vJ H-H2 rates
// >>chng 09 may 12, from 15.44 to 15.48, H2 - H2 collision update to Lee et al 2008
// >>chng 11 nov 16, from 15.48 to 15.84, adjust newmole monitors
// >>chng 12 jan 06, from 15.84 to 15.3, several H2 model changes
// >>chng 12 apr 09, from 15.3 to 15.37, update backbround CR to Indiolo_07 (8x larger)
monitor H2 column density level 1  3  15.37 error 0.1
//
c h2_orion_hii_pdr.in

05 dec 19,  had stopped at 1 pc, gas/dust got very cold and H2 stopped
forming, H2 went to H0 - this below the CO network out of the water.
stop at AV of 1000 instead.  Is this loss of H2 at low grain temperature
physical?  Is it ever seen?