#speed of light [m/s]
const 𝐜 = 299792458.0
#Planck constant [J*s]
const 𝐡 = 6.62607015e-34
#Boltzmann constant [J/Kelvin]
const 𝐤 = 1.38064852e-23
#Stefan-Boltzmann constant [W/m^2*Kelvin^4]
const 𝛔 = 5.67037442e-8
#gas constant [J/K*mole], equivalent to kB*Av
const 𝐑 = 8.31446262
#Pascals in 1 atm
const 𝐀 = 101325.0
#avogadros number [molecules/mole]
const 𝐍𝐚 = 6.02214076e23
#Dalton [kg] (mass of particle basically, also ≡ 1/𝐍𝐚/1000)
const 𝐃𝐚 = 1.66053907e-27
#gravitational constant [m^3/kg/s^2]
const 𝐆 = 6.6743e-11
#the Loschmidt number, but in molecules/cm^3 then squared [molecules^2/cm^6]
const 𝐋𝐨² = 7.21879268e38

#reference temperature of HITRAN database [K]
const 𝐓ᵣ = 296.0
#reference temperature [K] equivalent to 0 degrees Celsius
const 𝐓₀ = 273.15
#minimum pressure for certain temperature/pressure profiles
const 𝐏ₘᵢₙ = 1e-9