c..commons block and parameter declarations for the program atmos


c..input parameters
c..surfg = surface gravity of the atmosphere
      double precision surfg
      common /atmo2/   surfg


c..nlayer = maximum number of depth points in the atmosphere
c..layer  = a counter

      integer          nlayer,layer
      parameter        (nlayer = 500)
      common /atmo0/   layer


c..layer quantities
c..tau    = optical depth
c..dtau   = differential optical depth
c..depth  = the physical depth
c..temp   = temperature
c..den    = density
c..press  = gas pressure
c..xne    = number density of free electrons
c..kappa  = opacity
c..fracs  = ionization fractions

      double precision tau(nlayer),dtau(nlayer),depth(nlayer),
     1                 temp(nlayer),den(nlayer),press(nlayer),
     2                 xne(nlayer),kappa(nlayer)

      common /atmo3/   tau,dtau,depth,
     1                 temp,den,press,
     2                 xne,kappa

      double precision fracs(jstagemax,irowmax,nlayer)

      common /atmo4/   fracs