def METHOD_NAME(self, T):
    """Effective volumetric heat capacity [J.m-3.K-1]"""
    return (
        self.n.rho_c_p_cc(T) * self.geo.n.L_cc
        + self.n.rho_c_p(T) * self.geo.n.L
        + self.s.rho_c_p(T) * self.geo.s.L
        + self.p.rho_c_p(T) * self.geo.p.L
        + self.p.rho_c_p_cc(T) * self.geo.p.L_cc
    ) / self.geo.L