• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The Journal of Chemical Physics >Efficient dynamical correction of the transition state theory rate estimate for a flat energy barrier
【24h】

Efficient dynamical correction of the transition state theory rate estimate for a flat energy barrier

机译：平坦能垒的过渡态理论速率估计的有效动态校正

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The recrossing correction to the transition state theory estimate of a thermal rate can be difficult to calculate when the energy barrier is flat. This problem arises, for example, in polymer escape if the polymer is long enough to stretch between the initial and final state energy wells while the polymer beads undergo diffusive motion back and forth over the barrier. We present an efficient method for evaluating the correction factor by constructing a sequence of hyperplanes starting at the transition state and calculating the probability that the system advances from one hyperplane to another towards the product. This is analogous to what is done in forward flux sampling except that there the hyperplane sequence starts at the initial state. The method is applied to the escape of polymers with up to 64 beads from a potential well. For high temperature, the results are compared with direct Langevin dynamics simulations as well as forward flux sampling and excellent agreement between the three rate estimates is found. The use of a sequence of hyperplanes in the evaluation of the recrossing correction speeds up the calculation by an order of magnitude as compared with the traditional approach. As the temperature is lowered, the direct Langevin dynamics simulations as well as the forward flux simulations become computationally too demanding, while the harmonic transition state theory estimate corrected for recrossings can be calculated without significant increase in the computational effort. Published by AIP Publishing.
机译：当能垒平坦时，可能难以计算出对热速率的过渡态理论估计的重新交叉校正。例如，如果聚合物足够长以在初始状态能量阱和最终状态能量阱之间拉伸，同时聚合物珠在阻挡层上来回进行扩散运动，则会在聚合物逸出中出现此问题。我们提出了一种有效的方法，通过构造从过渡状态开始的一系列超平面并计算系统从一个超平面向另一个超平面推进到乘积的概率，来评估校正因子。这类似于在前向磁通采样中执行的操作，只是超平面序列从初始状态开始。该方法适用于从一口潜在的井中漏出多达64个珠粒的聚合物。对于高温，将结果与直接的Langevin动力学模拟以及正向通量采样进行比较，并且发现这三个速率估算值之间具有极好的一致性。与传统方法相比，在重新交叉校正的评估中使用一系列超平面可将计算速度提高一个数量级。随着温度的降低，直接的兰格文动力学模拟和正向通量模拟对计算的要求变得很高，而无需重新计算就可以计算出校正过的谐波过渡态理论估计值，而不会显着增加计算量。由AIP Publishing发布。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号