title PN with density propt R^-2 and filling factor
c this is an optically thin model, which will have a broad range
c of density but the same ionization parameter across the model.  
c the physical condtions should not vary by much across the structure
c
c commands controlling continuum =========
c continuum is hot blackbody at ~Ledd for solar mass
blackbody, t=5 luminosity=38
c
c commands for density & abundances =========
c the density will fall off as the inverse square of the radius, hence the name
hden 5 -2
init file "ism.ini"
c use default PN abundances but turn off quantum heating since
c we are not going to save the predicted near IR continuum
abundances planetary no qheat 
c
c commands controlling geometry  =========
c small filling factor so that region will be optically thin
filling factor -2
c set inner and outer radius 
radius 16 18
sphere
c
c other commands for details     =========
iterate
c 
c commands controlling output    =========
print line faint 1 
save performance "pn_sqrden.per"
save overview "pn_sqrden.ovr" last
save monitors "pn_sqrden.asr" last
save dr "pn_sqrden.dr" last
save molecules "pn_sqrden.mol" 
c
c commands giving the monitors    =========
//
// >>chng 01 mar 02, from 31.973 to 31.883 change H RT
// >>chng 04 jun 12, from 31.883 to 31.918, chng cont shield fcn
// >>chng 07 oct 22, from 31.918 to 31.831, resolve l-levels of h-like sequence
// >>chng 07 dec 15, from 31.831 to 31.871, X-ray grain merge
monitor line luminosity "totl" 4861 31.871
//
// >>chng 01 dec 21, inner shell yields, from 38.4 to 34.9
// >>chng 03 aug 22, to luminosity
// >>chng 07 dec 15, from 33.459 to 33.392, X-ray grain merge
monitor line luminosity "totl"  1549A 33.392 error 0.1
//
// >>chng 01 dec 21, inner shell yields, from 73.1 to 65.1
// >>chng 03 aug 22, to luminosity
// >>chng 07 dec 15, from 33.692 to 33.570, X-ray grain merge
monitor line luminosity "totl"  1240A 33.570 error 0.1
//
// >>chng 02 jun 15, from 299.75 to 283.3, line pump shielding
// >>chng 03 may 17, from 283.3 to 56.9, update pump more often 
// >>chng 03 aug 22, to luminosity
// >>chng 03 oct 30, from 33.647 to 33.624, diff zoning
// >>chng 04 mar 04, from 33.624 to 34.13, improv conv
// >>chng 09 mar 27, from 34.13 to 34.07 improve rigor esc prob & pop defns
// >>chng 09 apr 18, from 34.07 to 34.12, refactor evaluation of esc dest probs to occur with cooling
// >>chng 12 oct 22, from 34.12 to 33.62, zone tau in rt_line_one
monitor line luminosity "o  5" 630A 33.62 error 0.1
//
// >>chng 01 dec 21, inner shell yields, most changed by 5-7%
// >>chng 07 dec 15, from 4.353 to 4.319, X-ray grain merge
monitor temperature hydrogen 2 volume 4.319
//
// >>chng 01 dec 21, inner shell yields, most changed by 5-7%
// >>chng 04 may 10, from -4.957 to -4.982, slow drift
// >>chng 07 dec 15, from -4.982 to -4.942, X-ray grain merge
monitor ionization volume element Hydrogen 1 -4.942
//
monitor ionization volume element Hydrogen 2 -0.000
//
// >>chng 02 jul 23, from -2.824 to -2.799, slow drift
monitor ionization volume element Helium   2 -2.799
//
monitor ionization volume element Helium   3 -0.001
//
// >>chng 01 aug 23 from -3.505 to -3.478
// >>chng 06 nov 24, from -3.478 to -3.454, turn on Badnell RR
// >>chng 06 nov 29, from -3.454 to -3.303, Badnell DR turned on
// >>chng 11 jul 12, from -3.303 to -3.332, enable fit to Badnell DR suppression
monitor ionization volume element Carbon  3 -3.332
//
// >>chng 07 dec 15, from -1.568 to -1.521, X-ray grain merge
monitor ionization volume element Carbon  4 -1.521
//
monitor ionization volume element Carbon  5 -0.011
//
// >>chng 04 may 10, from -4.968 to -4.991, slow drift
// >>chng 07 dec 15, from -4.991 to -4.955, X-ray grain merge
monitor ionization radius element Hydrogen 1 -4.955
//
monitor ionization radius element Hydrogen 2 -0.000 
//
// >>chng 07 dec 15, from -2.835 to -2.798, X-ray grain merge
monitor ionization radius element Helium   2 -2.798
//
monitor ionization radius element Helium   3 -0.001
//
// >>chng 01 aug 23 from -3.573 to -3.546
// >>chng 06 nov 24, from -3.546 to -3.520, turn on Badnell RR
// >>chng 06 nov 29, from -3.520 to -3.295, Badnell DR turned on
// >>chng 11 jul 12, from -3.295 to -3.366, enable fit to Badnell DR suppression
// >>chng 12 nov 01, from -3.366 to -3.42, Chianti experimental levels, revised Badnell DR suppression
// >>chng 13 feb 02, from -3.42 to -3.327, BUGFIX, largely undo r6703 
monitor ionization radius element Carbon  3 -3.327
//
// >>chng 07 dec 15, from -1.579 to -1.532, X-ray grain merge
monitor ionization radius element Carbon  4 -1.532
//
monitor ionization radius element Carbon  5 -0.011
//
// >>chng 03 aug 22, from 17 to 25, line overlap
// >>chng 04 feb 15, from 25 to 15
// >>chng 04 sep 16, from 15 to 40 (!), incr edentrue convergence
// >>chng 08 dec 08, from 40 to 31.9, upper limit -> equals (r2515)
// >>chng 08 dec 13, from 31.9 to 47.76, merging newsolvers branch
// >>chng 09 jan 16, from 47.76 to 47.39, average of 10 runs
// >>chng 09 feb 23, from 47.39 to 45.72, remove otslin, otscon dampers (PR #84, r2758)
// >>chng 09 jun 15, from 45.72 to 44, gradual approach to outer edge
// >>chng 09 jun 26, from 44 to 45.77, remove several dampers
// >>chng 11 jun 14, from 45.77 to 57.6, new Te solver
// >>chng 11 jun 22, from 57.6 to 50.38, tune Te solver
// >>chng 11 aug 05, from 50.38 to 52.26, rescale low-lying HeI thresh photo cross sections
// >>chng 11 aug 05, from 52.26 to 50.66, fix mistake in r5333
// >>chng 12 mar 07, from 50.66 to 41.51, renorm to r5961 results
monitor itrzn 41.51
//
// >>chng 08 dec 08, from 160 to 136, upper limit -> equals (r2515)
// >>chng 09 jun 15, from 136 to 146, gradual approach to outer edge
monitor nzone 146 error 0.01
c pn_sqrden.in
c class pn 
c ========================================

Checks:
-	Zone thickness budgeting handled OK.
-       physical conditions nearly constant across computed structure