def sigma_Tee_Gotoh_Steward_1(Tc, Pc):
Pc = Pc/<NUM_LIT><EOL>sigma = <NUM_LIT>*(Tc/Pc)**(<NUM_LIT:1>/<NUM_LIT>)<EOL>return sigma<EOL>
r'''Calculates Lennard-Jones molecular diameter.
    Uses critical temperature and pressure. CSP method by [1]_.

    .. math::
        \sigma = 2.3647 \left(\frac{T_c}{P_c}\right)^{1/3}

    Parameters
    ----------
    Tc : float
        Critical temperature of fluid [K]
    Pc : float
        Critical pressure of fluid [Pa]

    Returns
    -------
    sigma : float
        Lennard-Jones molecular diameter, [Angstrom]

    Notes
    -----
    Original units of Pc are atm. Further regressions with other parameters
    were performed in [1]_ but are not included here, except for
    `sigma_Tee_Gotoh_Steward_2`.

    Examples
    --------
    >>> sigma_Tee_Gotoh_Steward_1(560.1, 4550000)
    5.48402779790962

    References
    ----------
    .. [1] Tee, L. S., Sukehiro Gotoh, and W. E. Stewart. "Molecular
       Parameters for Normal Fluids. Lennard-Jones 12-6 Potential." Industrial
       & Engineering Chemistry Fundamentals 5, no. 3 (August 1, 1966): 356-63.
       doi:10.1021/i160019a011