Performance of van der Waals Corrected Functionals for Guest Adsorption in the M2(dobdc) Metal-Organic Frameworks

Bess Vlaisavljevich; Johanna Huck; Zeric Hulvey; Kyuho Lee; Jarad A Mason; Jeffrey B Neaton; Jeffrey R Long; Craig M Brown; Dario Alfè; Angelos Michaelides; Berend Smit

doi:10.1021/acs.jpca.7b00076

Performance of van der Waals Corrected Functionals for Guest Adsorption in the M₂(dobdc) Metal-Organic Frameworks

J Phys Chem A. 2017 Jun 1;121(21):4139-4151. doi: 10.1021/acs.jpca.7b00076. Epub 2017 May 18.

Authors

Bess Vlaisavljevich, Johanna Huck, Zeric Hulvey^{1

2}, Kyuho Lee, Jarad A Mason, Jeffrey B Neaton³, Jeffrey R Long, Craig M Brown^{1

4}, Dario Alfè⁵, Angelos Michaelides⁶, Berend Smit⁷

Affiliations

¹ Center for Neutron Research, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States.
² Department of Materials Science and Engineering, University of Maryland , College Park, Maryland 20742 United States.
³ Kavli Energy Nanosciences Institute at Berkeley , Berkeley, California 94720, United States.
⁴ Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.
⁵ Department of Earth Sciences, Thomas Young Centre and London Centre for Nanotechnology, University College London , Gower Street, London WC1E 6BT, United Kingdom.
⁶ London Centre for Nanotechnology and Department of Physics and Astronomy, Thomas Young Centre, University College London , Gower Street, London WC1E 6BT, United Kingdom.
⁷ Institut des Sciences et Ingénierie Chimiques, Valais, Ecole Polytechnique Fédérale de Lausanne , Rue de l'Industrie 17, CH-1951 Sion, Switzerland.

Abstract

Small-molecule binding in metal-organic frameworks (MOFs) can be accurately studied both experimentally and computationally, provided the proper tools are employed. Herein, we compare and contrast properties associated with guest binding by means of density functional theory (DFT) calculations using nine different functionals for the M₂(dobdc) (dobdc^4- = 2,5-dioxido,1,4-benzenedicarboxylate) series, where M = Mg, Mn, Fe, Co, Ni, Cu, and Zn. Additionally, we perform Quantum Monte Carlo (QMC) calculations for one system to determine if this method can be used to assess the performance of DFT. We also make comparisons with previously published experimental results for carbon dioxide and water and present new methane neutron powder diffraction (NPD) data for further comparison. All of the functionals are able to predict the experimental variation in the binding energy from one metal to the next; however, the interpretation of the performance of the functionals depends on which value is taken as the reference. On the one hand, if we compare against experimental values, we would conclude that the optB86b-vdW and optB88-vdW functionals systematically overestimate the binding strength, while the second generation of van der Waals (vdW) nonlocal functionals (vdw-DF2 and rev-vdW-DF2) correct for this providing a good description of binding energies. On the other hand, if the QMC calculation is taken as the reference then all of the nonlocal functionals yield results that fall just outside the error of the higher-level calculation. The empirically corrected vdW functionals are in reasonable agreement with experimental heat of adsorptions but under bind when compared with QMC, while Perdew-Burke-Ernzerhof fails by more than 20 kJ/mol regardless of which reference is employed. All of the functionals, with the exception of vdW-DF2, predict reasonable framework and guest binding geometries when compared with NPD measurements. The newest of the functionals considered, rev-vdW-DF2, should be used in place of vdW-DF2, as it yields improved bond distances with similar quality binding energies.