temp (float): Temperature (K)
            press (float): Pressure (Pa)
            x (array_like): Molar composition
            phase (int): Calcualte root for specified phase
            dvdt (logical, optional): Calculate volume differentials with respect to temperature while pressure and composition are held constant. Defaults to None.
            dvdp (logical, optional): Calculate volume differentials with respect to pressure while temperature and composition are held constant. Defaults to None.
            dvdn (logical, optional): Calculate volume differentials with respect to mol numbers while pressure and temperature are held constant. Defaults to None.