This file explains the symbols used for various physical parameters in our data files.  Attached along with this
 read me file is attached two files for each model (1-8).  The first file gives the abundances,
 heating and cooling rates, dissociation rates, depth, visual extinction, and temperature (when pertinent).
  PLEASE PLOT OUR RESULTS USING THE AV(extend) COLUMN!!!!!

The second fine gives line intensities in units of ergs s-1 cm-2 str-1 for important fine
structure lines along with H2 line intensities.  The ordering and symbols used in the intensity file is
 explained in the lines output file.  The symbols for our other file, containing the physical parameters
 mentioned above, is listed below.

In our models we do not get a correct electron density if we do not include Si and Fe.  Therefore, we have
 included both elements in our models, even though the models were pre-defined to have only H, He, C, and O. 
 We have also not included the UMIST database sent in the e-mail.  This is because the way our code is set
 up now it would take a complete restructuring
of our molecular network to incorporate this.  This would likely take longer than the time remaining before
 the meeting begins.  Instead, we are attaching a separate file that includes a majority of the reactions
 in our chemical network.  This is named "chemical_network.txt".

There also needs to be changes to the original pdf file that details what each code can do.  We have marked
 in red places that should be checked for our code.  The reason for the initial confusion is that we answered
 the questions for a specific model and not for generalities.


Meaning of symbols for file containing all physical parameters except line intensities:

depth:	           Depth into cloud in centimeters

AV(point):         Visual extinction in magnitudes of a point source (not discounting forward 		   		   scattering)

AV(extend):        Visual extinction in magnitudes of an extended, diffuse source (discounting 		   		   forward scattering)

Te:    	           Electron temperature in Kelvin

H0:	           Density of neutral atomic hydrogen (all densities in units of cm-3)

H2:	           Density of Molecular Hydrogen

Co:	           Density of neutral atomic Carbon

C+:	           Density of ionized Carbon

Oo:	           Density of neutral atomic Oxygen
 
CO:	           Density of Carbon Monoxide

CH:	           Density of CH

OH:	           Density of OH

O2:		   Density of O2

e:		   electron density

N(H0):	           Column Density of neutral atomic hydrogen (cm-2)

N(H2):	           Column Density of Molecular Hydrogen

N(Co):	           Column Density of neutral atomic Carbon

N(C+):	           Column Density of ionized Carbon

N(Oo):	           Column Density of neutral atomic Oxygen
 
N(CO):	           Column Density of Carbon Monoxide

N(CH):	           Column Density of CH

N(OH):	           Column Density of OH

N(O2):		   Column Density of O2

N(e):		   electron Column density

H2(Sol):           Dissociation rate of Molecular Hydrogen due to Solomon process

H2(FrmGrn):	   Formation rate of Molecular Hydrogen on grain surfaces  

G0(DB96):  	   Flux of UV continuum between 6-13.6 eV

rate(CO):	   Dissociation rate of CO

rate(C):	   Photoionization rate of C

heat:	   	   Total heating
 
cool:	   	   Total cooling

GrnP:      	   Heating due to grain photoionization
  
COds:      	   Heating due to Carbon Monoxide photoionization

H2dH:      	   Heating due to Molecular Hydrogen dissociation

H2vH:      	   Heating due to collisions with Molecular Hydrogen

ChaT:      	   Heating due to charge transfer

CR H:      	   Heating due to cosmic rays

MgI:       	   Heavy element heating, Magnesium

SI:	   	   Heavy element heating, Sulpher

Si:        	   Heavy element heating, Silicon

Fe:        	   Heavy element heating, Iron

Na:        	   Heavy element heating, Sodium

Al:        	   Heavy element heating, Aluminum

C:         	   Heavy element heating, Carbon

C610:      	   Cooling due to [C I] 610 micron line

C370:      	   Cooling due to [C I] 370 micron line

C157:      	   Cooling due to [C II] 157 micron line

O63:       	   Cooling due to [O I] 63 micron line

O146:      	   Cooling due to [O I] 146 micron line

Cloudy only converges quantities that affect the physical conditions.  In the constant temperature case,
 heating and cooling are not balanced and there is no need to converge the heating to high accuracy.
  This introduces some noise in the H2 collisional deexcitation heating, since the level populations are
 converged to a tolerance that ensures an accurate spectrum, but the heating is not converged.  This is
 not an issue in the thermal balance models since heating and cooling related quantities are converged
 in this case.

We have put a great deal of work into the grain treatment.  This includes resolution of the grain size
 distribution into many size bins, with grain temperature, potential, etc, all determined self-consistently
 for each bin. Quantum heating is treated when important.  H2 formation on grain surfaces is done
 self-consistently in the context of this solution of the grain properties.  The H2 dissociation rate
 can be calculated by treating pumping to all rotational/vibrational levels, but for the time being it is  
calculated using the Draine and Bertoldi equation from 1996.