Constants.h

 
const double R_gas = 8314.46261815324;
const double N_A = 6.02214e26;
const double kb = R_gas / N_A;
 
const double mu_AO = 15.999;
const double mu_O2 = 31.999;
const double mu_He = 4.002602;
const double mu_N2 = 14.0067;
const double mu_Ar = 39.948;