def _compute_term2(self, C, mag, rjb):
        """
        Compute distance dependent terms (4th, 5th and 6th) in equation 3
        page 46. The factor 'RM' is computed according to the 2002 model
        (equation 4-3).
        """
        RM = np.sqrt(rjb ** 2 + (C['c7'] ** 2) *
                     np.exp(-1.25 + 0.227 * mag) ** 2)

        return (-C['c4'] * np.log(RM) -
                (C['c5'] - C['c4']) *
                np.maximum(np.log(RM / 100), 0) - C['c6'] * RM)