Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.
J Comput Chem. 2012 Jan 5;33(1):60-5. doi: 10.1002/jcc.21943. Epub 2011 Sep 29.
An ab initio molecular dynamics approach is combined with the semiclassical tunneling method of Makri and Miller, which is applied to estimations of tunneling splitting in the umbrella inversion of ammonia and the intramolecular hydrogen transfer in malonaldehyde. In the application to malonaldehyde, effects of multidimensionality are examined by assigning quantum zero-point energies only to significant vibrational modes and changing the amount of energy given to other degrees of freedom. The calculated tunneling splitting values are in good agreement with the corresponding experimental values for both molecules.
采用从头算分子动力学方法与 Makri 和 Miller 的半经典隧穿方法相结合，对氨的伞式反转和丙二醛的分子内氢转移中的隧穿分裂进行了估算。在丙二醛的应用中，通过仅对重要振动模式分配量子零点能，并改变赋予其他自由度的能量量，考察了多维性的影响。对于这两种分子，计算出的隧穿分裂值与相应的实验值吻合较好。
