title TH85 PDR with ISM grains
//>>refer Tielens, A.G.G.M., & Hollenbach, D., 1985, ApJ, 291, 747-754
c
c commands controlling continuum =========
c cosmic radiation background
background z=0
c cosmic ray background ionization and heating 
cosmic rays, background
c first continuum is FIR hot grain continuum produced in 
c unmodeled HII Region
blackbody, t = 75 K
intensity 2.7 (total)
c this is the attenuated hot stellar continuum
black 30000
intensity  2.204 range  0.4412 to 1 Ryd
c this will remove all ionizing radiation
extinguish 24 0
c
c commands controlling geometry  =========
c simulate effects of gas we do not model
double
c their turbulence
turbulence 2.7 km/sec
c stopping criteria
c this should be the one actually used
// >>chng 04 mar 13, bug in av, this asked for 10 and got 33.2,
// so keep same by changing stpo 
stop AV 33.2 extended 
c stop when gas is fully neutral
stop efrac -10
c stop when gas is cold
stop temperature 10 linear
c stop at thickness of 16.5 so that mole limit does not
c stop this calculation - that would make results very
c detail dependent
// >>chng 03 mar 08, from 16.5 to 16.3, so both th85orion, th85ism,
// stop for thickness, not C fully molecular
// >>chng 03 aug 28, stop at a few parsecs
stop thickness 19
c
c commands for density & abundances =========
hden 5.362
c this turns off some elements, and processes we don't need
c so needs to come before the elements 
init file="ism.ini"
abundances he -1.01 c -3.52 n-8 o-3.30 ne-8 mg-5.89
continue si -6.10 s -5.10 cl-7 ar-8 fe -6.60
c use ism abundances but turn of quantum heating 
grains ism, abundance log 0.16 no qheat 
c
c other commands for details     =========
c must iterate since many FIR MIR lines are optically thick
iterate 
c this is a closed geometry, in Orion, veil covers 2pi sr
sphere
c make Lyman lines very optically thick, which stops pumping by
c Balmer continuum
case b
c this should run cleanly - turn down number of allow conv fails
failures 3 
c
c commands controlling output    =========
normalize to "C  2" 157.6m 
c want the spectrum to be relative to this [C II] line
c uv lines are strongly pumped by stellar continuum, break out contribution
print line pump
print line optical depths
print ages
save performance "pdr_th85ism.per"
save overview last "pdr_th85ism.ovr"
save pdr last "pdr_th85ism.pdr"
// this only outputs major molecules 
save molecules last "pdr_th85ism.mol"
save dr last "pdr_th85ism.dr"
// this is to get all of H molecules 
save hydrogen physical conditions last "pdr_th85ism.hyd" 
save results last "pdr_th85ism.rlt"
save monitors last "pdr_th85ism.asr"
save continuum units microns last "pdr_th85ism.con"
save heating last "pdr_th85ism.het"
save cooling last "pdr_th85ism.col"
save hydrogen 21 cm last "pdr_th85ism.21cm"
save element magnesium last "pdr_th85ism.mag"
save species levels "pdr_th85ism.lev"
save species levels populations "pdr_th85ism.pop"
// these are for the grains
save grain extinction last  "pdr_th85ism.grnext"
save grain potential last   "pdr_th85ism.grnpot"
save grain temperature last "pdr_th85ism.grntem"
save grain charge last "pdr_th85ism.grnchr"
c
c commands giving the monitors    =========
// check that lines still recognized
table lines "LineList_PDR.dat"
// 
// >>chng 03 jan 29, all lines changed when went to distributed grains
// >>chng 03 mar 08, all lines changed when thickness made smaller to
// keep parallel with pdr_th85orion.in
// >>chng 03 aug 28, from -1.868 to -1.918, Nick Abel fix CO, greater depth
// >>chng 04 jun 12, from -1.918 to -1.891 chng cont shield fcn
// >>chng 04 jul 07, from -1.891 to -1.869, oh ct integ
// >>chng 04 dec 08, from -1.869 to -1.895, co-ion feedback, check converg
monitor line luminosity "c  2" 157.6m -1.895
//
// >>chng 03 apr 14, from -5.25 to -5.133, h t too low bug
// >>chng 03 jun 10, from -5.133 to -6.980, chng solomon rate
// >>chng 03 aug 28, from -6.980 to -3.629, Nick Abel fix CO, greater depth
// >>chng 03 sep 29, from -3.629 to -3.831, change stop to Av
// >>chng 04 apr 02, from -3.831 to -3.711, update co photodissoc rate
// >>chng 04 jun 12, from -3.711 to -3.592 chng cont shield fcn
// >>chng 04 jul 03, from -3.592 to -3.722, NA update H, CO chem net
// >>chng 10 mar 02, from -3.722 to -3.124, fix botches after CO model switch
// >>chng 10 jun 17, from -3.124 to -3.409, fix botches due to recent dBase cooling changes
monitor line luminosity "CO  " 520.1m -3.409 error 0.15
//
// >>chng 03 feb 10, from -3.52 to -3.57, new H3+ DR rate
// >>chng 03 feb 28, from -3.57 to -3.67, ?
// >>chng 03 apr 14, from -5.33 to -5.243, h t too low bug
// >>chng 03 jun 10, from -5.243 to -6.619, chng solomon rate
// >>chng 03 aug 28, from -6.619 to -3.139, Nick Abel fix CO, greater depth
// >>chng 03 sep 29, from -3.139 to -3.434, change stop to Av
// >>chng 03 oct 03, from -3.434 to -3.301, integ co ion solvers
// >>chng 04 mar 04, from -3.301 to -3.429, improv conv
// >>chng 04 apr 02, from -3.429 to -3.350, update co photodissoc rate
// >>chng 04 may 29, from -3.35 to -3.27, NA update H chem
// >>chng 04 jun 12, from -3.27 to -3.13 chng cont shield fcn
// >>chng 04 jul 03, from -3.13 to -3.24, NA update H, CO chem net
// >>chng 10 mar 02, from -3.24 to -2.72, fix botches after CO model switch
// >>chng 10 apr 11, from -2.72 to -2.784, more LAMDA models, add 13CO to chemistry
// >>chng 10 jun 17, from -2.784 to -3.181, fix botches due to recent dBase cooling changes
monitor line luminosity "CO  " 325.1m -3.181 error 0.15
//
// >>chng 04 apr 02, add this line
// >>chng 04 may 29, from -3.42 to -3.35, NA update H chem
// >>chng 04 jun 12, from -3.27 to -3.13 chng cont shield fcn
// >>chng 04 jun 12, from -3.35 to -3.23 chng cont shield fcn
// >>chng 04 jul 03, from -3.23 to -3.36, NA update H, CO chem net
// >>chng 10 mar 02, from -3.36 to -2.808, fix botches after CO model switch
// >>chng 10 jun 17, from -2.808 to -3.2, fix botches due to recent dBase cooling changes
monitor line luminosity "CO  " 371.5m  -3.2 error 0.15
//
// >>chng 03 jun 10, from -1.48 to -1.96 chng solomon rate
// >>chng 03 aug 28, from -1.96 to -1.60 Nick Abel fix CO, greater depth
// >>chng 03 sep 13, from -1.60 to -1.84, chng H2* reactions
// >>chng 03 nov 16, from -1.84 to -2.24, solomon th85 -> bd96
// >>chng 04 feb 09, from -2.24 to -2.40, more th85 -> bd96
// >>chng 04 mar 24, from -2.40 to -2.26, small changes, incr error
// >>chng 04 jun 12, from -2.26 to -2.16 chng cont shield fcn
// >>chng 05 jul 05, from -2.16 to -2.23, tune up
// >>chng 05 aug 03, from -2.23 to -2.45, NA update CO, H chem net
// >>chng 05 aug 06, from -2.45 to -2.28, H2 col dis rate chn
// >>chng 11 nov 16, from -2.28 to -2.48, adjust newmole monitors
monitor line luminosity "H2 l" 2.000m -2.48 error 0.2
//
// >>chng 03 may 17, from -2.882 to -2.749, update pump more often
// >>chng 03 may 23, from -2.749 to -1.861, bug in solomon process H2*
// >>chng 03 jun 10, from -1.861 to -1.592 chng solomon rate
// >>chng 03 aug 28, from -1.592 to -1.332 Nick Abel fix CO, greater depth
// >>chng 03 sep 13, from -1.33 to -1.94, chng H2* reactions
// >>chng 03 dec 10, from -1.94 to -2.01, key dr off H2 den
// >>chng 04 feb 09, from -2.01 to -1.76, more th85 -> bd96
// >>chng 04 mar 24, from -1.76 to -1.83, small changes
// >>chng 05 jul 05, from -2.16 to -2.35, cdsqte err, incr err
// >>chng 05 jul 05, from -1.83 to -1.79, tune up
// >>chng 05 aug 03, from -1.79 to -1.85, NA update CO, H chem net
// >>chng 05 aug 06, from -1.85 to -1.72, H2 col dis rate chn, inc err
// >>chng 05 dec 08, from -1.94 to -3.39, update to Elwert Solomon rate
monitor line luminosity "H2vH" 0 -3.39  error 0.2
//
// >>chng 03 jun 10, from -0.622 to -0.554 chng solomon rate
// >>chng 03 aug 28, from -0.554 to -0.617 Nick Abel fix CO, greater depth
// >>chg 04 jul 02, from -0.617 to -0.561, O H ct
// >>chng 04 jul 03, from -0.561 to -0.600, NA update H, CO chem net
// >>chng 04 jul 07, from -0.600 to -0.543, oh ct integ
// >>chng 04 sep 10, from -0.543 to -0.570, rewrite ion solver, full mtrx
// >>chng 04 dec 08, from -0.570 to -0.604, co-ion feedback, check converg
// >>chng 05 mar 25, from -0.604 to -0.574, renorm H pops in level solver
// >>chng 08 dec 13, from -0.574 to -0.6005, merging newsolvers branch
monitor line luminosity "o  1" 63.17m -0.6005
//
// >>chng 03 jun 10, from -1.80 to -1.858 chng solomon rate
// >>chng 03 aug 28, from -1.858 to -1.897 Nick Abel fix CO, greater depth
// >>chng 03 sep 13, from -1.897 to -1.927, chng H2* reactions
// >>chng 03 sep 23, from -1.927 to -1.809, better convergence, incr error
// >>chng 04 jul 07, from -1.809 to -1.751, oh ct integ
// >>chng 04 dec 08, from -1.751 to -1.810, co-ion feedback, check converg
// >>chng 07 dec 15, from -1.810 to -1.771, X-ray grain merge
// >>chng 10 mar 02, from -1.771 to -1.814, fix botches after CO model switch
monitor line luminosity "o  1" 145.5m -1.814 error 0.1
//
// >>chng 03 jun 10, from -0.503 to -0.471 chng solomon rate
// >>chng 03 aug 28, from -0.471 to -0.421 Nick Abel fix CO, greater depth
// >>chng 03 sep 13, from -0.421 to -0.448, chng H2* reactions
// >>chng 03 sep 23, from -0.448 to -0.505, better convergence, incr error
// >>chg 04 jul 02, from -0.505 to -0.466, O H ct
// >>chng 04 jul 03, from -0.466 to -0.506, NA update H, CO chem net
// >>chng 04 jul 07, from -0.506 to -0.447, oh ct integ
// >>chng 04 sep 10, from -0.447 to -0.475, rewrite ion solver, full mtrx
// >>chng 04 dec 08, from -0.475 to -0.513, co-ion feedback, check converg
// >>chng 05 mar 25, from -0.513 to -0.482, renorm H pops in level solver
// >>chng 07 dec 15, from -0.482 to -0.462, X-ray grain merge
// >>chng 08 dec 13, from -0.462 to -0.5097, merging newsolvers branch
monitor line luminosity "toth" 0 -0.5097
//
// >>chng 04 jun 12, add this line
// >>chg 04 jul 02, from -2.157 to -2.122, O H ct
// >>chng 04 jul 03, from -2.122 to -2.156, NA update H, CO chem net
// >>chng 04 jul 07, from -2.156 to -2.108, oh ct integ
// >>chng 04 sep 10, from -2.108 to -2.129, rewrite ion solver, full mtrx
// >>chng 04 dec 08, from -2.129 to -2.161, co-ion feedback, check converg
// >>chng 05 mar 25, from -2.161 to -2.130, renorm H pops in level solver
// >>chng 05 jul 05, from -2.130 to -2.12 tune up
// >>chng 08 dec 13, from -2.12 to -2.145, merging newsolvers branch
monitor line luminosity "Si 2" 34.81m  -2.145
//
// >>chng 03 aug 28, from 2.377 to 3.540 Nick Abel fix CO, greater depth
// >>chng 03 sep 29, from 3.540 to 2.640, change stop to Av
// >>chng 04 jul 02, from 2.640 to 2.669, O H ct
// >>chng 05 feb 23, from 2.669 to 2.643, small chng in diff field
monitor line luminosity "grat" 0 2.643
//
// >>chng 03 aug 28, from 97.3 to 44.9 Nick Abel fix CO, greater depth
// >>chng 03 sep 29, from 44.9 to 54.4 change stop to Av
monitor grain 1 temperature 54.4
//
// >>chng 03 aug 28, from 44.6 to 54.4, change stop to Av
monitor grain 2 temperature 54.4
//
// >>chng 03 aug 28, from -0.002 to -2.499 Nick Abel fix CO, greater depth
// >>chng 03 sep 29, from -2.499 to -0.904 change stop to Av
// >>chng 03 nov 02, from -0.904 to -0.901, next_radius change
// >>chng 03 nov 18, from -0.901 to -0.840, update co network
// >>chng 04 jan 27, from -0.840 to -0.775, update cosmic ray background
// >>chng 04 feb 13, from -0.775 to -0.745, He+ + H2 react added
// >>chng 04 feb 14, from -0.745 to -0.697, He+ + CO react updated
// >>chng 04 feb 21, from -0.697 to -0.518, further updates
// >>chng 04 apr 17, from -0.518 to -0.572, grn surf recom, better h mol conv
// >>chng 04 apr 19, from -0.572 to -0.718, Nick Abel update CO aft Leiden
// >>chng 04 jun 09, from -0.718 to -0.746, NA updat H chem net
// >>chng 04 jun 09, from -0.746 to -0.717, NA update H chem net
// >>chng 04 jul 03, from -0.717 to -0.751, NA update H, CO chem net, inc err
// >>chng 04 nov 08, from -0.751 to -0.724, drift up
monitor ionization Silicon 2 -0.724 err 0.1
//
// >>chng 04 feb 14, add this ion - He+ drives lots of chemistry
// >>chng 04 mar 24, from -8.491 to -9.027 small changes, incr error
// >>chng 04 apr 02, from -9.027 to -9.127, update co photodissoc rate
// >>chng 04 apr 17, from -9.127 to -8.428, grn surf recom, better h mol conv
// >>chng 04 may 19, from -8.428 to -8.386, RP update he-like seq
// >>chng 04 jun 09, from -8.386 to -8.325, NA update H chem net
// >>chng 04 jul 03, from -8.325 to -8.588, NA update H, CO chem net, inc err
// >>chng 05 feb 23, from -8.588 to -8.555, small chng in diff field
// >>chng 05 aug 03, from -8.55 to -8.51, NA update CO, H chem net
// >>chng 11 nov 16, from -8.51 to -8.594, adjust newmole monitors
// >>chng 12 apr 09, from -8.594 to -7.704, update CR backbround to Indriolo+07, ~8x larger
monitor ionization helium 2 -7.704 err 0.1
//
// >>chng 03 aug 28, from -0.053 to -2.690 Nick Abel fix CO, greater depth
// >>chng 03 sep 29, from -2.690 to -1.094 change stop to Av
// >>chng 04 feb 21, from -1.094 to -0.522, further updates
// >>chng 04 mar 13, from -0.522 to -0.544, drift down
// >>chng 04 mar 24, from -0.544 to -0.615 small changes
// >>chng 04 apr 17, from -0.615 to -0.835, grn surf recom, better h mol conv
// >> in vstudio debug and release do not get same answer, follow is mean
// >>chng 06 mar 02, from -0.82 to -0.78, NA Fe0, Mg0, <-> Si+, S+, C+ ct,
// also energy barrier for H + (CH and CH2) reactions
monitor ionization magnesium 2 -0.78 error 0.1
//
// >>chng 03 aug 28, from -0.0376 to -2.701 Nick Abel fix CO, greater depth
// >>chng 03 sep 29, from -2.701 to -1.104 change stop to Av
// >>chng 04 feb 21, from -1.104 to -0.809, further updates
// >>chng 04 apr 17, from -0.809 to -0.902, grn surf recom, better h mol conv
// >> in vstudio debug and release do not get same answer, follow is mean
monitor ionization sulphur 2 -0.888 error 0.1
//
// >>chng 03 aug 28, from -0.025 to -2.629 Nick Abel fix CO, greater depth
// >>chng 03 sep 29, from -2.629 to -1.036 change stop to Av
// >>chng 04 jan 28, from -1.036 to -1.005, update cr background heating
// >>chng 04 feb 13, from -1.005 to -1.029, He+ + H2 react added
// >>chng 04 feb 21, from -1.029 to -0.040, further updates
// >>chng 04 mar 24, from -0.040 to -0.102 small changes
// >>chng 04 apr 17, from -0.102 to -0.795, grn surf recom, better h mol conv
// >> in vstudio debug and release do not get same answer, follow is mean
// >>chng 12 apr 09, from -0.781 to -0.731, update CR backbround to Indriolo+07, ~8x larger
monitor ionization iron 2 -0.731 error 0.1
//
// >>chng 03 aug 28, from -0.150 to -2.615 Nick Abel fix CO, greater depth
// >>chng 03 sep 10, from -2.615 to -2.663, better resolution of H2*
// >>chng 03 sep 11, from -2.663 to -2.583, better resolution of H2*
// >>chng 03 sep 16, from -2.583 to -0.614, Nick Abel, better cons, add mol ion
// >>chng 03 sep 17, from -0.614 to -0.651, incr error, depends on CO formation
// >>chng 03 sep 23, from -0.651 to -0.432, better convergence, incr error
// >>chng 03 oct 03, from -0.432 to -0.547, integ co ion solvers
// >>chng 03 nov 02, from -0.547 to -0.606, next_radius change
// >>chng 04 jan 27, from -0.606 to -0.565, update cosmic ray background
// >>chng 04 feb 21, from -0.565 to -0.400, further updates
// >>chng 04 apr 02, from -0.400 to -0.151, update co photodissoc rate
// >>chng 04 apr 19, from -0.151 to -0.108, Nick Abel update CO aft Leiden
// >>chng 04 may 29, from -0.108 to -0.05, NA update H chem
// >>chng 04 jun 28, from -0.05 to -1.096, include mole in ion frac sum
// >>chng 05 feb 23, from -1.10 to -1.07, small chng in diff field
monitor ionization carbon 2 -1.07 error 0.1
//
// >>chng 03 aug 28, from 302 to 438 Nick Abel fix CO, greater depth
// >>chng 03 sep 13, from 438 to 391, chng H2* reactions
// >>chng 04 feb 21, from 391 to 289 further updates
// >>chng 04 jun 14, from 289 to 303, slow drift
// >>chg 04 jul 02, from 303 to 335 O H ct
// >>chng 04 jul 03, from 335 to 302 NA update H, CO chem net
// >>chng 04 jul 07, from 302 to 354 oh ct integ
// >>chng 04 sep 10, from 354 to 325 rewrite ion solver, full mtrx
// >>chng 04 dec 08, from 325 to 299 co-ion feedback, check converg
// >>chng 05 mar 25, from 299 to 326 renorm H pops in level solver
// >>chng 05 jul 05, from 326 to 323 tune up
// >>chng 07 oct 22, from 323 to 357, resolve l-levels of h-like sequence
// >>chng 08 apr 10, from 357 to 337, change default h-like levels, other minor changes
// >>chng 08 jun 25, from 337 to 354 add source/sink to ioniz ladder
// >>chng 08 dec 13, from 354 to 309.2, merging newsolvers branch
monitor temperature carbon 2 309.2
// 
// >>chng 03 may 03 add these two
// >>chng 03 jun 10, from 21.33 to 21.209 chng solomon rate
// >>chng 03 aug 28, from 21.209 to 24.061 Nick Abel fix CO, greater depth
// >>chng 03 sep 29, from 24.061 to 22.451 change stop to Av
monitor H2 column density 22.451 error 0.1 
//
// >>chng 03 jun 10, from 15.20 to 13.236 chng solomon rate
// >>chng 03 aug 28, from 13.236 to 20.458 Nick Abel fix CO, greater depth
// >>chng 03 sep 10, from 20.458 to 20.377, better resolution of H2*
// >>chng 03 sep 11, from 20.377 to 20.499, better resolution of H2*
// >>chng 03 sep 16, from 20.499 to 20.839, Nick Abel, better cons, add mol ion
// >>chng 03 sep 29, from 20.839 to 19.176 change stop to Av
// >>chng 04 mar 25, from 19.176 to 19.13, finer convergence
// >>chng 04 apr 02, from 19.13 to 19.205, update co photodissoc rate
// >>chng 04 jul 07, from 19.205 to 19.148 oh ct integ
// >>chng 05 mar 25, from 19.15 to 19.18 renorm H pops in level solver
monitor CO column density 19.18 error 0.15
//
// >>chng 04 apr 19, add these four
// >>chng 04 may 29, from 16.25 to 16.14, NA update H chem
// >>chng 04 jun 09, from 16.14 to 16.19, NA updat H chem net
// >>chng 04 jun 12, from 16.19 to 16.13 chng cont shield fcn
// >>chng 04 jul 03, from 16.13 to 16.25 NA update H, CO chem net
// >>chng 04 jul 07, from 16.25 to 16.205 oh ct integ
// >>chng 04 jul 16, from 16.20 to 16.25, update chem
// >>chng 04 jul 27, from 16.25 to 16.91, NA implement N chem
// >>chng 04 aug 01, from 16.91 to 16.66, improv C converg
// >>chng 04 aug 15, from 16.66 to 16.22, NA improve conv heav el, inc err
// >>chng 05 jun 26, from 16.22 to 16.34, make Federman chem the default
// >>chng 10 mar 02, from 16.34 to 16.25, fix botches after CO model switch
// >>chng 11 nov 16, from 16.25 to 16.34, adjust newmole monitors
// >>chng 12 apr 09, from 16.34 to 16.64, update CR backbround to Indriolo+07, ~8x larger
monitor H2O column density 16.64 error 0.20 
//
// >>chng 04 may 19, from 17.97 to 17.86, NA add few moles, lots reactions
// >>chng 04 may 29, from 17.86 to 17.43, NA update H chem
// >>chng 04 jun 09, from 17.43 to 17.48, NA updat H chem net
// >>chng 04 jun 20, from 17.48 to 17.43, ? 
// >>chng 04 jul 03, from 17.43 to 17.87 NA update H, CO chem net
// >>chng 04 jul 07, from 17.87 to 17.816 oh ct integ
// >>chng 04 jul 16, from 17.82 to 17.86, update chem
// >>chng 04 jul 17, from 17.86 to 17.68, NA update chem net
// >>chng 04 jul 27, from 17.68 to 17.51, NA implement N chem
// >>chng 04 aug 01, from 17.51 to 17.62, improv C converg
// >>chng 04 sep 08, from 17.62 to 17.69, rewrt auger/grain ion solver, inc err
// >>chng 05 aug 03, from 17.69 to 17.46, NA update CO, H chem net
// >>chng 05 aug 24, from 17.46 to 17.35, NA update CO cr ion rate
// >>chng 08 Feb 10, from 17.35 to 17.18, adjust CR& secondary effic
// >>chng 11 nov 16, from 17.18 to 17.3, adjust newmole monitors
// >>chng 12 aug 21, from 17.3 to 17.38, fix CRPHOT botches and HD crash
monitor O2 column density 17.38 error 0.2 
// 
// >>chng 04 may 19, from 15.18 to 15.13, NA update CO network, add mole
// >>chng 04 may 29, from 15.13 to 14.92, NA update H chem
// >>chng 04 jun 09, from 14.92 to 14.96, NA updat H chem net
// >>chng 04 jun 20, from 14.96 to 14.91, ? 
// >>chng 04 jul 03, from 14.91 to 15.11 NA update H, CO chem net
// >>chng 04 jul 07, from 15.11 to 15.07 oh ct integ
// >>chng 04 jul 16, from 15.07 to 15.11, update chem
// >>chng 04 jul 17, from 15.11 to 15.15, NA update chem net
// >>chng 04 jul 27, from 17.15 to 15.83, NA implement N chem
// >>chng 04 aug 01, from 15.83 to 15.55, improv C converg
// >>chng 04 aug 15, from 15.55 to 15.09, NA improve conv heav el, inc err
// >>chng 04 sep 10, from 15.09 to 15.18 rewrite ion solver, full mtrx
// >>chng 05 aug 24, from 15.18 to 15.25, NA update CO cr ion rate
// >>chng 12 apr 09, from 15.25 to 15.71, update CR backbround to Indriolo+07, ~8x larger
monitor SiO column density 15.71 error 0.20 
// 
// >>chng 04 may 19, from 14.30 to 14.25, NA add few moles, lots reactions
// >>chng 04 may 29, from 14.25 to 13.93, NA update H chem
// >>chng 04 jun 09, from 13.93 to 13.97, NA updat H chem net
// >>chng 04 jun 14, from 13.97 to 13.93, slow drift
// >>chng 04 jul 03, from 13.93 to 14.19 NA update H, CO chem net
// >>chng 04 jul 07, from 14.19 to 14.14 oh ct integ
// >>chng 04 jul 30, from 14.14 to 14.02, NA implement N chem
// >>chng 04 aug 01, from 14.02 to 14.09, improv C converg, inc err
// >>chng 04 aug 15, from 14.09 to 14.18, NA improve conv heav el, inc err
// >>chng 05 feb 23, from 14.18 to 14.10, small chng in diff field
// >>chng 05 jun 26, from 14.10 to 14.18, make Federman chem the default
// >>chng 05 dec 08, from 14.18 to 14.10, update to Elwert Solomon rate
// >>chng 10 jun 17, from 14.1 to 14.18, fix botches due to recent dBase cooling changes
// >>chng 12 apr 09, from 14.18 to 15.02, update CR backbround to Indriolo+07, ~8x larger
monitor OH column density 15.02 error 0.20
// 
// >>chng 05 sep 30, add these 5
// >>chng 12 apr 09, from 9.95 to 10.85, update CR backbround to Indriolo+07, ~8x larger
monitor column density H2+  10.85 error 0.1
// >>chng 12 apr 09, from 12.89 to 13.79, update CR backbround to Indriolo+07, ~8x larger
monitor column density H3+  13.79 error 0.1
monitor column density H2g  22.44 error 0.1
// 
// >>chng 05 dec 08, from 16.70 to 16.17, update to Elwert Solomon rate
// >>chng 11 nov 16, from 16.17 to 16.1, adjust newmole monitors
monitor column density H2*  16.1 error 0.1
// 
// >>chng 05 dec 08, from 7.96 to 7.99, update to Elwert Solomon rate
// >>chng 11 nov 16, from 7.99 to 7.847, adjust newmole monitors
// >>chng 12 apr 09, from 7.847 to 8.745, update CR backbround to Indriolo+07, ~8x larger
monitor column density HeH+ 8.745 error 0.1
// 
//
// >>chng 03 mar 04, from <390 to <430, finer d(H2)/dr criteria
// >>chng 03 aug 28, from 430 to 600 Nick Abel fix CO, greater depth
// >>chng 04 jun 03, from 600 to 660, finer dr off molecules
// >>chng 04 jul 17, from 660 to 800 NA update chem net
// >>chng 04 aug 04, from 800 to 900, finer dr as chem net changes
// >>chng 08 dec 08, from 900 to 837, upper limit -> equals (r2515)
// >>chng 09 jan 16, from 837 to 839 (error 0.02), average of 10 runs
// >>chng 11 oct 12, from 839 to 873, scale iso highest pcs to be consistent with recomb topoff
// >>chng 12 apr 09, from 873 to 827, update CR backbround to Indriolo+07, ~8x larger
// >>chng 12 oct 22, from 827 to 808, zone tau in rt_line_one
monitor nzone 808 error 0.02
//
// >chng 03 aug 28, add this
// >>chng 03 nov 02, from 5 to 6.5 next_radius change
// >>chng 04 feb 15, from 6.5 to 5
// >>chng 04 jun 28, from 5 to 8 include mole in ion frac sum
// >>chng 04 aug 15, from 8 to 6 NA improve conv heav el, inc err
// >>chng 08 dec 08, from 6 to 3.89, upper limit -> equals (r2515)
// >>chng 08 dec 13, from 3.89 to 11.65, merging newsolvers branch
// >>chng 09 jan 16, from 11.65 to 11.8 (error 0.05), average of 10 runs
// >>chng 11 jun 14, from 11.8 to 10.67, new Te solver
// >>chng 11 jun 22, from 10.67 to 9.772, tune Te solver
// >>chng 11 dec 16, from 9.772 to 9.223, adjust botches due to recent iso recomb changes
// >>chng 12 feb 27, from 9.772 to 10.21, Upgrade to Chianti 7
// >>chng 12 mar 16, from 10.21 to 9.16, merge Chianti 7 into newmole
// >>chng 12 apr 02, from 9.16 to 8.479, Chianti 7 change, gcc 4.4.6 wolkje
// >>chng 12 oct 17, from 8.479 to 8.885, Improved CRD esc p
// >>chng 12 nov 01, from 8.885 to 8.485, Chianti experimental levels, revised Badnell DR suppression
monitor itrzn 8.485 error 0.05
//
c pdr_th85ism.in
c class pdr 
c ========================================
c 

This is the Tielens and Hollenbach (1985a, b) standard model of
the Orion photodissociation region (PDR).  Specifically,
this is my attempt at their Table 2 of paper 2, ApJ 291,  p749.
The case b command appears because the Lyman lines are
vastly optically thick in this environment. 
If the command is removed the Lyman lines will be optically thin,
which will result in fast fluorescent excitation of the
(nearly totally neutral) hydrogen atom.

// >>refer	model	pdr	Tielens, A. G. G. M., & Hollenbach, D. 1985a, ApJ, 291, 722
// >>refer	model	pdr	Tielens, A. G. G. M., & Hollenbach, D. 1985b, ApJ, 291, 746