  We propose a novel mathematical approach for the calculation of near-zero
energy states by solving potentials which are isospectral with the original
one. For any potential, families of strictly isospectral potentials (with very
different shape) having desirable and adjustable features are generated by
supersymmetric isospectral formalism. The near-zero energy Efimov state in the
original potential is effectively trapped in the deep well of the isospectral
family and facilitates more accurate calculation of the Efimov state.
Application to the first excited state in 4He trimer is presented.
