Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany.
Phys Chem Chem Phys. 2012 Jan 21;14(3):1223-34. doi: 10.1039/c1cp22446h. Epub 2011 Dec 5.
We explore the energy landscape of (MgF(2))(3) on both the empirical and ab initio level using the threshold algorithm. In order to determine the energy landscape and the dynamics of the trimer we investigate not only the stable isomers but also the barriers separating these isomers. Furthermore, we study the probability flows in order to estimate the stability of all the isomers found. We find that there is reasonable qualitative agreement between the ab initio and empirical potential, and important features such as sub-basins and energetic barriers follow similar trends. However, we observe that the energies are systematically different for the less compact clusters, when comparing empirical and ab initio energies. Since the underlying motivation of this work is to identify the possible clusters present in the gas phase during a low-temperature atom beam deposition synthesis of MgF(2), we employ the same procedure to additionally investigate the energy landscape of the tetramer. For this case, however, we use only the empirical potential.
我们使用阈算法在经验和从头算水平上探索了 (MgF(2))(3) 的能量景观。为了确定三聚体的能量景观和动力学，我们不仅研究了稳定的异构体，还研究了分离这些异构体的势垒。此外，我们研究了概率流，以估计所发现的所有异构体的稳定性。我们发现，从头算和经验势之间存在合理的定性一致性，并且类似的趋势遵循亚盆地和能量势垒等重要特征。然而，我们观察到，当比较经验和从头算能量时，对于不太紧凑的簇，能量系统地不同。由于这项工作的基本动机是在 MgF(2) 的低温原子束沉积合成过程中识别气相中可能存在的团簇，因此我们采用相同的程序来进一步研究四聚体的能量景观。然而，对于这种情况，我们仅使用经验势。
