Some limitations on: Analytic approximate eigenvalues by a new technique. Application to sextic anharmonic potentials, D.D. Almeida and P. Martin, Results. in. Phys. 8, 140–145 (2018)

Abstract

New technique suggested by Almeida and Martin, can be only used to calculate eigenvalues of single well oscillators. As such the method will fail drastically even to compute eigenvalues of single properly non-linear oscillator of the type H=p2+x2+<x2>x4. Further new technique can hardly ever be used to calculate eigenvalues of any double-well oscillator. Without the calculation of wave characteristics mod square |Ψ|2 or oblique way by way of expectation value <A> the stated paper loses its intention as widely usual method in eigenvalue relation.