title: Comment on "Calculations for the one-dimensional soft Coulomb problem and the hard Coulomb limit".
abstract: In the referred paper, the authors use a numerical method for solving ordinary differential equations and a softened Coulomb potential -1/√[x(2)+β(2)] to study the one-dimensional Coulomb problem by approaching the parameter β to zero. We note that even though their numerical findings in the soft potential scenario are correct, their conclusions do not extend to the one-dimensional Coulomb problem (β=0). Their claims regarding the possible existence of an even ground state with energy -∞ with a Dirac-δ eigenfunction and of well-defined parity eigenfunctions in the one-dimensional hydrogen atom are questioned.
authors.affiliation: Facultad de Física, Universidad Veracruzana, Xalapa de Enríquez CP 91000 Veracruz, Mexico.
authors.forename: M A
authors.initials: MA
authors.lastname: Carrillo-Bernal
authors.affiliation: Departamento de Física, Universidad Autónoma Metropolitana, Unidad Iztapalapa, Apartado Postal 55-534, Iztapalapa CP 09340 D. F., Mexico.
authors.forename: H N
authors.initials: HN
authors.lastname: Núñez-Yépez
authors.affiliation: Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, CP 04510 México D. F., Mexico.
authors.forename: A L
authors.initials: AL
authors.lastname: Salas-Brito
authors.affiliation: Facultad de Matemáticas, Universidad Autónoma de Yucatán, Periférico Norte, Tablaje C 13615, Mérida, Yucatán, Mexico.
authors.forename: Didier A
authors.initials: DA
authors.lastname: Solis