Nanotechnology and Advanced Materials Laboratory, Department of Chemical Engineering, University of Patras , 26500 GR Patras, Greece.
School of Chemical Engineering, National Technical University of Athens (NTUA) , GR-15780 Athens, Greece.
J Am Chem Soc. 2016 Mar 9;138(9):3218-27. doi: 10.1021/jacs.6b00135. Epub 2016 Feb 29.
We present the ground state and energetically low structures of BenH2n nanoclusters as predicted using density functional theory (DFT) and employing the M06 meta-hybrid exchange-correlation functional. Results using the M06 functional are benchmarked against high accuracy coupled-cluster CCSD(T) and found to be in excellent agreement. For small values of n, the linear or polymeric form is the lowest energy geometry, while for sizes larger, n > 9 ring type and link type structures are the energetically lowest configurations. This trend has also been observed through ab initio molecular dynamics (AIMD) simulations at finite temperatures. In addition to the binding energies of the structures we report on polymerization energies, Be-H bond energies with respect to coordination details, hydrogen desorption energies of saturated and oversaturated species, as well as computed infrared spectra of all the ground state and energetically low lying structures presented. Furthermore, we find that the saturated polymeric forms of the nanoclusters cannot retain molecular hydrogen, in contrast to what is expected when zero point energy corrections are not taken into account.
我们使用密度泛函理论（DFT）并采用 M06 混合交换相关泛函预测了 BenH2n 纳米团簇的基态和低能结构。使用 M06 泛函的结果与高精度耦合簇 CCSD(T) 进行了基准测试，结果非常吻合。对于较小的 n 值，线性或聚合形式是最低能量的几何形状，而对于较大的 n > 9，环型和链接型结构是能量最低的构型。通过有限温度下的从头算分子动力学（AIMD）模拟也观察到了这种趋势。除了报告结构的结合能外，我们还报告了聚合能、Be-H 键能与配位细节的关系、饱和和过饱和物种的氢脱附能，以及所有呈现的基态和低能结构的计算红外光谱。此外，我们发现纳米团簇的饱和聚合形式不能保留氢气，这与不考虑零点能修正时的预期相反。
