def Z_7_func(*, a_0, X, v_r, B_θ, ρ, Z_5, norm_kepler, C, v_φ, Z_4):
    """
    Compute the value of the variable Z_7
    """
    return Z_5 + B_θ ** 2 * (X / norm_kepler + a_0 * (C - v_r / (2 *
        norm_kepler)) * (2 * norm_kepler * v_φ - Z_4 * X) / (v_φ ** 2 * ρ *
        norm_kepler - Z_4 * a_0 * v_r))
