Explicitly correlated interaction potential energy profile of imidazole + CO2 complex

• DOI: 10.1007/s00214-015-1657-z
• Publication Date: 2015-04-21T14:34:09Z
• Authors: S. Dalbouha; M. Prakash; V. Timón; N. Komiha; M. Hochlaf; M. L. Senent
• Keywords: Zeolitic imidazolate framework; Coupled cluster; Imidazole; Potential energy surface

© 2015, Springer-Verlag Berlin Heidelberg. In this paper, the interaction potential energy profiles corresponding to the imidazole + CO2 system are determined using explicitly correlated coupled-cluster methods (CCSD(T)-F12) in combination with the VTZ-F12 basis set. The imidazole + CO2 van der Waals complex, which represents a relevant system for the study of the CO2 capture and storage in new materials, such as the zeolitic imidazolate frameworks (ZIFs), shows three different equilibrium geometries, two planar ones of Cs symmetry and one C1 structure. Their geometrical parameters and harmonic frequencies, as well as the one-dimensional potential energy profiles for the complex formation processes, are provided. Intermolecular bindings occur through the imidazole nitrogen atoms. The interaction energy depends strongly on the two molecule relative orientations. The full-dimensional intermolecular potentials show a significant anisotropy. The implications for the macromolecular simulations of the CO2 capture and sequestration in ZIFs are discussed. Preliminary tests of various theoretical methods (DFT and ab initio) have been performed to search for a methodology suitable for further application in large systems such as the substituted imidazoles (Zn-imidazoles or R-imidazoles). In these tests, the results obtained using CCSD(T)-F12 are employed as benchmarks. Suddenly, the MP2 theory competes with the explicitly correlated methods. MP2 theory corrects the deviation of the density functional theory calculations in the long-range region<br/>10 pags.; 6 figs.; 3 tabs.<br/>This research was supported by a Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Community Framework Program under Grant No. PIRSES-GA-2012-31754, the COST Action CM1401, the COST Action CM1405 and the FIS2013-40626-P project of the MINECO, Spain. This work has benefited from a French government grant managed by ANR within the frame of the national program investments for the future ANR-11-LABX-022-01. M.P. thanks, the financial support from the LABEX Modélisation & Expérimentation pour la Construction Durable (MMCD, U. Paris-Est). The authors acknowledge the CTI (CSIC) and CESGA for computing facilities.<br/>Peer Reviewed<br/>