title: Comment on "Thomson rings in a disk".
abstract: We have found that the minimum energy configuration of N=395 charges confined in a disk and interacting via the Coulomb potential, reported by Cerkaski et al. [Phys. Rev. E 91, 032312 (2015)PLEEE81539-375510.1103/PhysRevE.91.032312], is not a global minimum of the total electrostatic energy. We have identified a large number of configurations with lower energy, where defects are present close to the center of the disk; thus, the formation of a hexagonal core and valence circular rings for the centered configurations, predicted by the model of the above-mentioned reference, is not supported by numerical evidence, and the configurations obtained with this model cannot be used as a guide for the numerical calculations, as claimed by the authors.
authors.affiliation: Facultad de Ciencias, CUICBAS, Universidad de Colima, Bernal Díaz del Castillo 340, Colima, Colima, Mexico.
authors.forename: Paolo
authors.initials: P
authors.lastname: Amore