2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/148587The stretching and bending vibrations of methane are studied in a local anharmonic model of molecular vibrations. The use of symmetry-adapted operators reduces the eigenvalue problem to block diagonal form. For the 44 observed energies we obtain a fit with a standard deviation of 0.81 cm$^{-1}$ (and a r.m.s. deviation of 1.16 cm$^{-1}$).revised and updated version: 13 pages, 3 tables, Revista Mexicana de Fisica, in pressChemical Physicstext