Published Research - Department of Chemistry
Ab initio study of hydrogen adsorption on benzenoid linkers in metal–organic framework materials
Date of this Version
We have computed the energies of adsorption of molecular hydrogen on a number of molecular linkers in metal–organic framework solid materials using density functional theory (DFT) and ab initio molecular orbital methods. We find that the hybrid B3LYP (Becke three-parameter Lee–Yang–Parr) DFT method gives a qualitatively incorrect prediction of the hydrogen binding with benzenoid molecular linkers. Both local-density approximation (LDA) and generalized gradient approximation (GGA) DFT methods are inaccurate in predicting the values of hydrogen binding energies, but can give a qualitatively correct prediction of the hydrogen binding. When compared to the more accurate binding- energy results based on the ab initio Møller–Plesset second-order perturbation (MP2) method, the LDA results may be viewed as an upper limit while the GGA results may be viewed as a lower limit. Since the MP2 calculation is impractical for realistic metal–organic framework systems, the combined LDA and GGA calculations provide a cost-effective way to assess the hydrogen binding capability of these systems.
Published in Journal Of Physics: Condensed Matter 19 (2007), 386220 (8 pp); doi:10.1088/0953- 8984/19/38/386220. Online at http://stacks.iop.org/JPhysCM/19/386220 Copyright © 2007 IOP Publishing Ltd. Used by permission.