Dipartimento di Fisica, Università degli Studi di Trento, Via Sommarive 14, Povo (Trento) I-38123, Italy
J Chem Phys. 2011 Jul 21;135(3):034103. doi: 10.1063/1.3609244.
We study the role of quantum fluctuations of atomic nuclei in the real-time dynamics of non-equilibrium macro-molecular transitions. To this goal we introduce an extension of the dominant reaction pathways formalism, in which the quantum corrections to the classical overdamped Langevin dynamics are rigorously taken into account to order ħ(2). We first illustrate our approach in simple cases, and compare with the results of the instanton theory. Then we apply our method to study the C7(eq) → C7(ax) transition of alanine dipeptide. We find that the inclusion of quantum fluctuations can significantly modify the reaction mechanism for peptides. For example, the energy difference which is overcome along the most probable pathway is reduced by as much as 50%.
我们研究了原子核量子涨落在非平衡宏观分子跃迁实时动力学中的作用。为此，我们引入了一种主导反应途径形式的扩展，其中严格考虑到了对经典过阻尼朗之万动力学的 ħ(2)阶量子修正。我们首先在简单情况下说明我们的方法，并与瞬子理论的结果进行比较。然后，我们将我们的方法应用于研究丙氨酸二肽的 C7(eq) → C7(ax) 跃迁。我们发现，量子涨落的包含可以显著改变肽的反应机制。例如，沿着最可能的途径克服的能量差减少了多达 50%。
