To test the hypothesis of atmospheric carbon dioxide or methane storage in metastable clathrate, a theoretical formalism is developed to model and simulate the spectra of the CO2 or CH4 molecule trapped in clathrates. 12-6 Lennard-Jones atom-atom potentials are used to account for short and long range interactions between the atoms of the trapped molecules and atoms of H2O molecules of the cage. Effective electric charges are used for electrostatic interactions with H2O molecules. The calculations were performed on clathrates of type I, with a small and a large cage to determine equilibrium configurations for both CO2 and CH4 and vibrational shifts were determined for CO2 in an undistorted trapping nano-cage.
