def Lee_Kesler(T, Tc, Pc, omega):
Tr = T/Tc<EOL>f0 = <NUM_LIT> - <NUM_LIT>/Tr - <NUM_LIT>*log(Tr) + <NUM_LIT>*Tr**<NUM_LIT:6><EOL>f1 = <NUM_LIT> - <NUM_LIT>/Tr - <NUM_LIT>*log(Tr) + <NUM_LIT>*Tr**<NUM_LIT:6><EOL>return exp(f0 + omega*f1)*Pc<EOL>
r'''Calculates vapor pressure of a fluid at arbitrary temperatures using a
    CSP relationship by [1]_; requires a chemical's critical temperature and
    acentric factor.

    The vapor pressure is given by:

    .. math::
        \ln P^{sat}_r = f^{(0)} + \omega f^{(1)}

        f^{(0)} = 5.92714-\frac{6.09648}{T_r}-1.28862\ln T_r + 0.169347T_r^6

        f^{(1)} = 15.2518-\frac{15.6875}{T_r} - 13.4721 \ln T_r + 0.43577T_r^6

    Parameters
    ----------
    T : float
        Temperature of fluid [K]
    Tc : float
        Critical temperature of fluid [K]
    Pc : float
        Critical pressure of fluid [Pa]
    omega : float
        Acentric factor [-]

    Returns
    -------
    Psat : float
        Vapor pressure at T [Pa]

    Notes
    -----
    This equation appears in [1]_ in expanded form.
    The reduced pressure form of the equation ensures predicted vapor pressure 
    cannot surpass the critical pressure.

    Examples
    --------
    Example from [2]_; ethylbenzene at 347.2 K.

    >>> Lee_Kesler(347.2, 617.1, 36E5, 0.299)
    13078.694162949312

    References
    ----------
    .. [1] Lee, Byung Ik, and Michael G. Kesler. "A Generalized Thermodynamic
       Correlation Based on Three-Parameter Corresponding States." AIChE Journal
       21, no. 3 (1975): 510-527. doi:10.1002/aic.690210313.
    .. [2] Reid, Robert C..; Prausnitz, John M.;; Poling, Bruce E.
       The Properties of Gases and Liquids. McGraw-Hill Companies, 1987.