A quantum generalization of intrinsic reaction coordinate using path integral centroid coordinates.
A quantum generalization of intrinsic reaction coordinate using path integral centroid coordinates.
复制标题
使用路径积分质心坐标对本征反应坐标进行量子推广。
DOI：
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发表时间：
2012
影响因子：
4.4
通讯作者：
H. Fujisaki
中科院分区：
文献类型：
--
作者：
M. Shiga;H. Fujisaki
我们提出了一个推广的量子多体系统的内禀反应坐标（IRC）的质量加权环聚合物的质心在时间路径积分理论。这种新型的反应坐标，可以称为“质心IRC”，对应于连接反应物和产物状态的最小自由能路径，其中最少量的可逆功施加到量子核的质心，即，质心我们提供了一个数值程序来获得质心IRC的第一性原理的基础上结合从头算路径积分模拟与弦方法。将此方法应用于NH（3）分子和N（2）H（5）（-）离子及其氘代同位素，研究了核量子效应在分子内和分子间质子转移反应中的重要性.我们发现，在分子内质子转移（反转）的NH（3），质心变量的自由能垒减少了约20%的量相比，在室温下的经典之一。在N（2）H（5）（-）的分子间质子转移中，质心IRC大大偏离“经典”IRC，自由能垒因量子效应而降低得更为剧烈.
We propose a generalization of the intrinsic reaction coordinate (IRC) for quantum many-body systems described in terms of the mass-weighted ring polymer centroids in the imaginary-time path integral theory. This novel kind of reaction coordinate, which may be called the "centroid IRC," corresponds to the minimum free energy path connecting reactant and product states with a least amount of reversible work applied to the center of masses of the quantum nuclei, i.e., the centroids. We provide a numerical procedure to obtain the centroid IRC based on first principles by combining ab initio path integral simulation with the string method. This approach is applied to NH(3) molecule and N(2)H(5) (-) ion as well as their deuterated isotopomers to study the importance of nuclear quantum effects in the intramolecular and intermolecular proton transfer reactions. We find that, in the intramolecular proton transfer (inversion) of NH(3), the free energy barrier for the centroid variables decreases with an amount of about 20% compared to the classical one at the room temperature. In the intermolecular proton transfer of N(2)H(5) (-), the centroid IRC is largely deviated from the "classical" IRC, and the free energy barrier is reduced by the quantum effects even more drastically.
DOI：
10.1073/pnas.1016653108
发表时间：
2011-04-19
影响因子：
11.1
作者：
Li, Xin-Zheng;Walker, Brent;Michaelides, Angelos
通讯作者：
Michaelides, Angelos
影响因子：
3.4
作者：
Gan, Wenxun;Yang, Sichun;Roux, Benoit
通讯作者：
Roux, Benoit
影响因子：
4.4
作者：
Ovchinnikov, Victor;Karplus, Martin;Vanden-Eijnden, Eric
通讯作者：
Vanden-Eijnden, Eric