Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, Moscow, 119991, Russia.
Phys Chem Chem Phys. 2013 Nov 21;15(43):18815-21. doi: 10.1039/c3cp53189a.
Understanding molecular interactions of graphene is a question of key importance to design new materials and catalytic systems for practical usage. Although for small models good accuracy was demonstrated in theoretical analysis with ab initio and density functional methods, the application to real-size systems with thousands of atoms is currently hardly possible on routine bases due to the high computational cost. In the present study we report that incorporation of dispersion correction led to the principal improvement in the description of graphene systems at a semi-empirical level. The accuracy and the scope of the calculations were explored for a wide range of molecules adsorbed on graphene surfaces (H2, N2, CO, CO2, NH3, CH4, H2O, benzene, naphthalene, coronene, ovalene and cyclohexane). As a challenging parameter, the calculated adsorption energy of aromatic hydrocarbons on graphene Eads = -1.8 ± 0.1 kcal mol(-1) (per one carbon atom) at the PM6-DH2 level was in excellent agreement with the experimentally determined value of Eads = -1.7 ± 0.3 kcal mol(-1). The dispersion corrected semi-empirical method was found to be a remarkable computational tool suitable for everyday laboratory studies of real-size graphene systems. Significant performance improvement (ca. 10(3) times faster) and excellent accuracy were found as compared to the ωB97X-D density functional calculations.
理解石墨烯的分子相互作用对于设计新型材料和用于实际用途的催化体系至关重要。尽管对于小模型，从头算和密度泛函方法的理论分析已经证明了很好的准确性，但由于计算成本高，目前几乎不可能将其应用于具有数千个原子的实际规模体系。在本研究中，我们报告称，在半经验水平上，引入分散校正导致对石墨烯体系的描述得到了主要改善。我们探索了一系列吸附在石墨烯表面的分子（H2、N2、CO、CO2、NH3、CH4、H2O、苯、萘、蒄、轮烯和环己烷）的计算准确性和范围。作为一个具有挑战性的参数，在 PM6-DH2 水平下，计算得到的芳香烃在石墨烯上的吸附能 Eads = -1.8 ± 0.1 kcal mol(-1)（每个碳原子）与实验确定的 Eads = -1.7 ± 0.3 kcal mol(-1)非常吻合。结果发现，经过分散校正的半经验方法是一种非常适合于实际规模石墨烯体系日常实验室研究的计算工具。与 ωB97X-D 密度泛函计算相比，它具有显著的性能提升（约快 10(3)倍）和优异的准确性。
