The role of errors related to DFT methods in calculations involving ion pairs of ionic liquids
详细信息 查看全文
- 作者：Isabel Lage-Estebanez ; Lourdes del Olmo ; Rafael Ló ; pez and José ; Manuel Garcí ; a de la Vega
- 刊名：Journal of Computational Chemistry
- 出版年：2017
- 出版时间：March 30, 2017
- 年：2017
- 卷：38
- 期：8
- 页码：530-540
- 全文大小：1048K
- ISSN：1096-987X
文摘
Ionic liquids (ILs) play a key role in many chemical applications. As regards the theoretical approach, ILs show added difficulties in calculations due to the composition of the ion pair and to the fact that they are liquids. Although density functional theory (DFT) can treat this kind of systems to predict physico–chemical properties, common versions of these methods fail to perform accurate predictions of geometries, interaction energies, dipole moments, and other properties related to the molecular structure. In these cases, dispersion and self-interaction error (SIE) corrections need to be introduced to improve DFT calculations involving ILs. We show that the inclusion of dispersion is needed to obtain good geometries and accurate interaction energies. SIE needs to be corrected to describe the charges and dipoles in the ion pair correctly. The use of range–separated functionals allows us to obtain interaction energies close to the CCSD(T) level.