coeff_CO    = [30.87,   -1.285E-2,    2.789E-5,    -1.272E-8]
coeff_H2    = [27.14,    9.274E-3,   -1.381E-5,     7.645E-9]
coeff_CH4   = [19.25,    5.213E-2,    1.197E-5,    -1.132E-8]
coeff_N2    = [31.15,   -1.357E-2,    2.680E-5,    -1.168E-8]
coeff_CH3OH = [21.15,    7.092E-2,    2.587E-5,    -2.852E-8]