def rho_to_V(rho, MW):
    """
    Return the molar volume (V) in m^3/mol given the density (rho) in
    kg/m^3 and molecular weight (MW) in g/mol.

    .. math::
        V = \\left(\\frac{1000 \\rho}{MW}\\right)^{-1}

    Parameters
    ----------
    rho : float
        Density, [kg/m^3]
    MW : float
        Molecular weight, [g/mol]

    Returns
    -------
    V : float
        Molar volume, [m^3/mol]

    Examples
    --------
    >>> V(652.9, 86.18)
    0.00013199571144126206

    """
    return MW / rho / 1000.0
