Within quantum chemistry the abbreviation ``HGE" means ``Harris,
Engerholm and Gwinn", ``an early forerunner of discrete-variable
methods" from 1965. In the letter in question, two calculations of
resonances in even-parity potentials are presented which report
the progress achieved in the earlier two ``naive" proposals (viz.,
of the hypervirial perturbation method [1] and of the matrix
diagonalization method [2] by the same authors)  when the HEG
approach is incorporated. In the first (viz., a two-peak gaussian)
example a disagreement is detected with the results of ref. [5].
In the second (viz., a power-law-perturbed inverted-gaussian)
example a spectral-concentration phenomenon described in ref. [8]
is made clearly visible.


MR2186599 Killingbeck, John P.; Grosjean, Alain; Jolicard, Georges
A complex variable form of the HEG technique.
J. Phys. A 38 2005), no. 42, L695--L699.
65F15 (15A90)