def diffusion_coefficient(mol_vol, wat_viscosity = 10**-3):
    """
    Return the diffusion coefficent [m²/s]
    source : (HNS-MS)

    Parameters
    ----------
    mol_vol : Molar volume of the component [mol/m³]
    wat_viscosity : Dynamic viscosity of water [Pa s]

    """
    return (13.26*10**-5)/((wat_viscosity*1000)**1.14 * (mol_vol*100**3)**0.589)/(100*100)