{
  "ALIASES": [
    "isobutane", 
    "Isobutane", 
    "ISOBUTANE", 
    "R600A", 
    "R600a"
  ], 
  "ANCILLARIES": {
    "hL": {
      "A": [
        -58829.34158938623, 
        170.5451796929163, 
        0.6162711654306408, 
        -0.0053018559436187425, 
        2.0943523112936617e-05, 
        -5.0332329315311905e-08, 
        6.651481526074004e-11, 
        -3.797381783161163e-14
      ], 
      "B": [
        1, 
        -0.002421824472244289
      ], 
      "_note": "coefficients are in increasing order; input in K, output in J/mol; value is enthalpy minus hs_anchor enthalpy", 
      "max_abs_error": 303.0532870873549, 
      "max_abs_error_units": "J/mol", 
      "type": "rational_polynomial"
    }, 
    "hLV": {
      "A": [
        29860.67391574815, 
        -6.670353030511229, 
        -1.6393845888763268, 
        0.013392367462910941, 
        -5.8029757085730367e-05, 
        1.4457295673686832e-07, 
        -1.9569457108152776e-10, 
        1.128629830081101e-13
      ], 
      "B": [
        1, 
        -0.0024207623619944708
      ], 
      "_note": "coefficients are in increasing order; input in K, output in J/mol; value is enthalpy minus hs_anchor enthalpy", 
      "max_abs_error": 703.6829473859673, 
      "max_abs_error_units": "J/mol", 
      "type": "rational_polynomial"
    }, 
    "melting_line": {
      "BibTeX": "Buecker-JPCRD-2006B", 
      "T_m": 113.55, 
      "parts": [
        {
          "T_0": 113.73, 
          "T_max": 127, 
          "T_min": 113.73, 
          "a": [
            1953637130.9
          ], 
          "p_0": 0.0219, 
          "t": [
            6.12
          ]
        }
      ], 
      "type": "polynomial_in_Tr"
    }, 
    "pL": {
      "T_r": 407.817, 
      "Tmax": 407.81699999999915, 
      "Tmin": 113.73000000000002, 
      "description": "p' = pc*exp(Tc/T*sum(n_i*theta^t_i))", 
      "max_abserror_percentage": 0.025709437298837567, 
      "n": [
        0.4893216106119911, 
        -6.629467799666135, 
        0.27190214385479383, 
        -0.013142408151644676, 
        -3.250782332365992, 
        -0.43922387424664594
      ], 
      "reducing_value": 3629000.0, 
      "t": [
        0.83, 
        0.964, 
        2.071, 
        2.407, 
        3.825, 
        15.511
      ], 
      "type": "pL", 
      "using_tau_r": true
    }, 
    "pV": {
      "T_r": 407.817, 
      "Tmax": 407.81699999999915, 
      "Tmin": 113.73000000000002, 
      "description": "p'' = pc*exp(Tc/T*sum(n_i*theta^t_i))", 
      "max_abserror_percentage": 0.019699846909193575, 
      "n": [
        -48.02915589537987, 
        43.34653680580028, 
        -1.4421317283854331, 
        -3.1322275225078413, 
        5.203481182010376, 
        -6.173022897817098
      ], 
      "reducing_value": 3629000.0, 
      "t": [
        1.082, 
        1.108, 
        1.463, 
        4.045, 
        13.157, 
        14.042
      ], 
      "type": "pV", 
      "using_tau_r": true
    }, 
    "rhoL": {
      "T_r": 407.817, 
      "Tmax": 407.81699999999915, 
      "Tmin": 113.73000000000002, 
      "description": "rho' = rhoc*(1+sum(n_i*theta^t_i))", 
      "max_abserror_percentage": 0.26628224832738745, 
      "n": [
        2.0418147224188545, 
        0.4363922893974425, 
        1.915261424521202, 
        -2.1807762762122045, 
        1.068664850362356, 
        -6.816247938174933
      ], 
      "reducing_value": 3879.756788283995, 
      "t": [
        0.356, 
        0.824, 
        3.142, 
        3.696, 
        6.863, 
        18.441
      ], 
      "type": "rhoLnoexp", 
      "using_tau_r": false
    }, 
    "rhoV": {
      "T_r": 407.817, 
      "Tmax": 407.81699999999915, 
      "Tmin": 113.73000000000002, 
      "description": "rho'' = rhoc*exp(Tc/T*sum(n_i*theta^t_i))", 
      "max_abserror_percentage": 0.4922366156330571, 
      "n": [
        -2.8656855559386294, 
        0.7330458189287201, 
        -4.254613288675131, 
        2.9956235180226516, 
        -5.671641417558254, 
        0.14361022568133902
      ], 
      "reducing_value": 3879.756788283995, 
      "t": [
        0.37, 
        0.502, 
        1.021, 
        2.003, 
        3.403, 
        10.717
      ], 
      "type": "rhoV", 
      "using_tau_r": true
    }, 
    "sL": {
      "A": [
        -343.0315785084629, 
        3.0682816312100214, 
        -0.01632828350995562, 
        6.602197691846063e-05, 
        -1.8407331130955436e-07, 
        3.2273113331974106e-10, 
        -3.205767809115736e-13, 
        1.358686041344578e-16
      ], 
      "B": [
        1, 
        -0.002417095837950523
      ], 
      "_note": "coefficients are in increasing order; input in K, output in J/mol/K; value is entropy minus hs_anchor entropy", 
      "max_abs_error": 0.8029163090499019, 
      "max_abs_error_units": "J/mol/K", 
      "type": "rational_polynomial"
    }, 
    "sLV": {
      "A": [
        1116.4949820862637, 
        -19.569418706926673, 
        0.17278224442122414, 
        -0.0009207053379985635, 
        3.058212117538665e-06, 
        -6.1998714249116026e-09, 
        7.024193243467152e-12, 
        -3.4072896284755546e-15
      ], 
      "B": [
        1, 
        -0.0023698092291068932
      ], 
      "_note": "coefficients are in increasing order; input in K, output in J/mol/K; value is entropy minus hs_anchor entropy", 
      "max_abs_error": 2.580887010861343, 
      "max_abs_error_units": "J/mol/K", 
      "type": "rational_polynomial"
    }, 
    "surface_tension": {
      "BibTeX": "Mulero-JPCRD-2012", 
      "Tc": 407.81, 
      "a": [
        -0.01639, 
        0.06121
      ], 
      "description": "sigma = sum(a_i*(1-T/Tc)^n_i)", 
      "n": [
        2.102, 
        1.304
      ]
    }
  }, 
  "CAS": "75-28-5", 
  "ENVIRONMENTAL": {
    "ASHRAE34": "UNKNOWN", 
    "FH": 4, 
    "GWP100": -1.0, 
    "GWP20": -1.0, 
    "GWP500": -1.0, 
    "HH": 1, 
    "Name": "IsoButane", 
    "ODP": -1.0, 
    "PH": 0
  }, 
  "EOS": [
    {
      "BibTeX_CP0": "", 
      "BibTeX_EOS": "Buecker-JPCRD-2006B", 
      "STATES": {
        "hs_anchor": {
          "T": 448.59100000000007, 
          "T_units": "K", 
          "hmolar": 43954.8222411498, 
          "hmolar_units": "J/mol", 
          "p": 5887949.640936111, 
          "p_units": "Pa", 
          "rhomolar": 3491.7811094555955, 
          "rhomolar_units": "mol/m^3", 
          "smolar": 144.5636715682779, 
          "smolar_units": "J/mol/K"
        }, 
        "reducing": {
          "T": 407.81, 
          "T_units": "K", 
          "p": 3629000, 
          "p_units": "Pa", 
          "rhomolar": 3879.756788283995, 
          "rhomolar_units": "mol/m^3"
        }, 
        "sat_min_liquid": {
          "T": 113.73, 
          "T_units": "K", 
          "p": 0.022891027562310824, 
          "p_units": "Pa", 
          "rhomolar": 12737.62445835364, 
          "rhomolar_units": "mol/m^3"
        }, 
        "sat_min_vapor": {
          "T": 113.73, 
          "T_units": "K", 
          "p": 0.02289066053179942, 
          "p_units": "Pa", 
          "rhomolar": 2.4207430191901677e-05, 
          "rhomolar_units": "mol/m^3"
        }
      }, 
      "T_max": 575, 
      "T_max_units": "K", 
      "Ttriple": 113.73, 
      "Ttriple_units": "K", 
      "accentric": 0.183531783208, 
      "accentric_units": "-", 
      "alpha0": [
        {
          "a1": 11.60865546, 
          "a2": -5.29450411, 
          "type": "IdealGasHelmholtzLead"
        }, 
        {
          "a": 3.05956619, 
          "type": "IdealGasHelmholtzLogTau"
        }, 
        {
          "n": [
            4.94641014, 
            4.09475197, 
            15.6632824, 
            9.73918122
          ], 
          "t": [
            0.951277902, 
            2.387895885, 
            4.346904269, 
            10.36885864
          ], 
          "type": "IdealGasHelmholtzPlanckEinstein"
        }, 
        {
          "a1": -17.6081648486994, 
          "a2": 10.3134499204439, 
          "reference": "IIR", 
          "type": "IdealGasHelmholtzEnthalpyEntropyOffset"
        }
      ], 
      "alphar": [
        {
          "d": [
            1, 
            1, 
            1, 
            2, 
            3, 
            4, 
            4, 
            1, 
            1, 
            2, 
            7, 
            8, 
            8, 
            1, 
            2, 
            3, 
            3, 
            4, 
            5, 
            5, 
            10, 
            2, 
            6
          ], 
          "l": [
            0, 
            0, 
            0, 
            0, 
            0, 
            0, 
            0, 
            1, 
            1, 
            1, 
            1, 
            1, 
            1, 
            2, 
            2, 
            2, 
            2, 
            2, 
            2, 
            2, 
            2, 
            3, 
            3
          ], 
          "n": [
            2.0686820727966, 
            -3.6400098615204, 
            0.51968754427244, 
            0.17745845870123, 
            -0.12361807851599, 
            0.045145314010528, 
            0.03047647996598, 
            0.75508387706302, 
            -0.85885381015629, 
            0.036324009830684, 
            -0.01954879945055, 
            -0.004445239290496, 
            0.004641076366646, 
            -0.071444097992825, 
            -0.080765060030713, 
            0.15560460945053, 
            0.0020318752160332, 
            -0.10624883571689, 
            0.039807690546305, 
            0.016371431292386, 
            0.00053212200682628, 
            -0.0078681561156387, 
            -0.0030981191888963
          ], 
          "t": [
            0.5, 
            1, 
            1.5, 
            0, 
            0.5, 
            0.5, 
            0.75, 
            2, 
            2.5, 
            2.5, 
            1.5, 
            1, 
            1.5, 
            4, 
            7, 
            3, 
            7, 
            3, 
            1, 
            6, 
            0, 
            6, 
            13
          ], 
          "type": "ResidualHelmholtzPower"
        }, 
        {
          "beta": [
            150, 
            200
          ], 
          "d": [
            1, 
            2
          ], 
          "epsilon": [
            0.85, 
            1
          ], 
          "eta": [
            10, 
            10
          ], 
          "gamma": [
            1.16, 
            1.13
          ], 
          "n": [
            -0.042276036810382, 
            -0.0053001044558079
          ], 
          "t": [
            2, 
            0
          ], 
          "type": "ResidualHelmholtzGaussian"
        }
      ], 
      "critical_region_splines": {
        "T_max": 407.817, 
        "T_min": 406.8534813947396, 
        "_note": "Coefficients for the critical cubic spline.  T = c[0]*rho^3 + c[1]*rho^2 + c[2]*rho + c[3] with rho in mol/m^3 and T in K", 
        "cL": [
          -9.941703745512649e-10, 
          1.1401780743865456e-05, 
          -0.04357798580431196, 
          463.3231742084145
        ], 
        "cV": [
          0.0, 
          -1.0815601793791963e-06, 
          0.00839238089576816, 
          391.53680162488934
        ], 
        "rhomolar_max": 4815.639002152002, 
        "rhomolar_min": 2935.903033135107
      }, 
      "gas_constant": 8.314472, 
      "gas_constant_units": "J/mol/K", 
      "molar_mass": 0.0581222, 
      "molar_mass_units": "kg/mol", 
      "p_max": 35000000, 
      "p_max_units": "Pa", 
      "pseudo_pure": false
    }
  ], 
  "NAME": "IsoButane", 
  "REFPROP_NAME": "ISOBUTAN", 
  "STATES": {
    "critical": {
      "T": 407.817, 
      "T_units": "K", 
      "p": 3629000.0, 
      "p_units": "Pa", 
      "rhomolar": 3879.756788283995, 
      "rhomolar_units": "mol/m^3"
    }, 
    "triple_liquid": {
      "T": 113.73, 
      "T_units": "K", 
      "p": 0.022891027562310824, 
      "p_units": "Pa", 
      "rhomolar": 12737.62445835364, 
      "rhomolar_units": "mol/m^3"
    }, 
    "triple_vapor": {
      "T": 113.73, 
      "T_units": "K", 
      "p": 0.02289066053179942, 
      "p_units": "Pa", 
      "rhomolar": 2.4207430191901677e-05, 
      "rhomolar_units": "mol/m^3"
    }
  }, 
  "TRANSPORT": {
    "conductivity": {
      "BibTeX": "Perkins-JCED-2002-Isobutane", 
      "critical": {
        "GAMMA": 0.0496, 
        "R0": 1.03, 
        "gamma": 1.239, 
        "qD": 1520540217.5, 
        "type": "simplified_Olchowy_Sengers", 
        "zeta0": 1.94e-10
      }, 
      "dilute": {
        "A": [
          -0.00237901, 
          0.0106601, 
          0.0215811
        ], 
        "B": [
          1.0
        ], 
        "T_reducing": 407.85, 
        "T_reducing_units": "K", 
        "m": [
          0
        ], 
        "n": [
          0, 
          1, 
          2
        ], 
        "type": "ratio_of_polynomials"
      }, 
      "residual": {
        "B": [
          -0.0411789, 
          0.146805, 
          -0.11919, 
          0.0410226, 
          -0.00488704, 
          0.0476346, 
          -0.128445, 
          0.107565, 
          -0.0385968, 
          0.00520901
        ], 
        "T_reducing": 407.85, 
        "T_reducing_units": "K", 
        "d": [
          1, 
          2, 
          3, 
          4, 
          5, 
          1, 
          2, 
          3, 
          4, 
          5
        ], 
        "rhomass_reducing": 224.4, 
        "rhomass_reducing_units": "kg/m^3", 
        "t": [
          0, 
          0, 
          0, 
          0, 
          0, 
          -1, 
          -1, 
          -1, 
          -1, 
          -1
        ], 
        "type": "polynomial"
      }
    }, 
    "viscosity": {
      "BibTeX": "Vogel-IJT-1999", 
      "dilute": {
        "C": 2.1357e-08, 
        "a": [
          0.53583008, 
          -0.4562963, 
          0.049911282
        ], 
        "molar_mass": 0.0581222, 
        "molar_mass_units": "kg/mol", 
        "t": [
          0, 
          1, 
          2
        ], 
        "type": "collision_integral"
      }, 
      "epsilon_over_k": 307.55, 
      "epsilon_over_k_units": "K", 
      "higher_order": {
        "T_reduce": 407.817, 
        "T_reduce_units": "K", 
        "a": [
          0.000103511763411, 
          -0.000312670896234, 
          0.000145253750239, 
          -0.000210649894193, 
          0.000386269696509, 
          -0.000214963015527, 
          0.00011258036092, 
          -0.000223242033154, 
          0.000119114788598, 
          -1.819097459e-05, 
          3.60438957232e-05, 
          -2.1396018405e-05
        ], 
        "d1": [
          2, 
          2, 
          2, 
          3, 
          3, 
          3, 
          4, 
          4, 
          4, 
          5, 
          5, 
          5
        ], 
        "d2": [
          1
        ], 
        "f": [
          0.0019403760699
        ], 
        "g": [
          2.33859774637, 
          2.352551508384381
        ], 
        "gamma": [
          0, 
          0, 
          0, 
          0, 
          0, 
          0, 
          0, 
          0, 
          0, 
          0, 
          0, 
          0
        ], 
        "h": [
          0, 
          -0.5
        ], 
        "l": [
          1, 
          1, 
          1, 
          1, 
          1, 
          1, 
          1, 
          1, 
          1, 
          1, 
          1, 
          1
        ], 
        "p": [
          1
        ], 
        "q": [
          0
        ], 
        "rhomolar_reduce": 3860, 
        "rhomolar_reduce_units": "mol/m^3", 
        "t1": [
          0, 
          1, 
          2, 
          0, 
          1, 
          2, 
          0, 
          1, 
          2, 
          0, 
          1, 
          2
        ], 
        "t2": [
          0
        ], 
        "type": "modified_Batschinski_Hildebrand"
      }, 
      "initial_density": {
        "b": [
          -19.572881, 
          219.73999, 
          -1015.3226, 
          2471.01251, 
          -3375.1717, 
          2491.6597, 
          -787.26086, 
          14.085455, 
          -0.34664158
        ], 
        "t": [
          0, 
          -0.25, 
          -0.5, 
          -0.75, 
          -1.0, 
          -1.25, 
          -1.5, 
          -2.5, 
          -5.5
        ], 
        "type": "Rainwater-Friend"
      }, 
      "sigma_eta": 4.6445e-10, 
      "sigma_eta_units": "m"
    }
  }
}