Wahiduzzaman Mohammad, Walther Christian F J, Heine Thomas
School of Engineering and Science, Jacobs University Bremen, D-28759 Bremen, Germany.
J Chem Phys. 2014 Aug 14;141(6):064708. doi: 10.1063/1.4892670.
The role of nuclear quantum effects on the adsorption of molecular hydrogen in metal-organic frameworks (MOFs) has been investigated on grounds of Grand-Canonical Quantized Liquid Density-Functional Theory (GC-QLDFT) calculations. For this purpose, we have carefully validated classical H2-host interaction potentials that are obtained by fitting Born-Oppenheimer ab initio reference data. The hydrogen adsorption has first been assessed classically using Liquid Density-Functional Theory and the Grand-Canonical Monte Carlo methods. The results have been compared against the semi-classical treatment of quantum effects by applying the Feynman-Hibbs correction to the Born-Oppenheimer-derived potentials, and by explicit treatment within the GC-QLDFT. The results are compared with experimental data and indicate pronounced quantum and possibly many-particle effects. After validation calculations have been carried out for IRMOF-1 (MOF-5), GC-QLDFT is applied to study the adsorption of H2 in a series of MOFs, including IRMOF-4, -6, -8, -9, -10, -12, -14, -16, -18, and MOF-177. Finally, we discuss the evolution of the H2 quantum fluid with increasing pressure and lowering temperature.
基于巨正则量子化液体密度泛函理论（GC - QLDFT）计算，研究了核量子效应在金属有机框架材料（MOFs）中对分子氢吸附的作用。为此，我们仔细验证了通过拟合玻恩 - 奥本海默从头算参考数据获得的经典H₂ - 主体相互作用势。首先使用液体密度泛函理论和巨正则蒙特卡罗方法对氢吸附进行了经典评估。通过对玻恩 - 奥本海默导出的势应用费曼 - 希布斯校正以及在GC - QLDFT内进行显式处理，将结果与量子效应的半经典处理进行了比较。将结果与实验数据进行比较，结果表明存在明显的量子效应以及可能的多粒子效应。在对IRMOF - 1（MOF - 5）进行验证计算后，应用GC - QLDFT研究了一系列MOF中H₂的吸附情况，包括IRMOF - 4、- 6、- 8、- 9、- 10、- 12、- 14、- 16、- 18和MOF - 177。最后，我们讨论了随着压力升高和温度降低H₂量子流体的演变情况。
