扩散量子蒙特卡洛方法计算氢提取反应的能垒
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- 英文论文题名：Reaction Barriers of Hydrogen-Abstraction Reactions with Diffuse Quantum Monte Carlo Method
- 论文作者：周晓俊 ; 王繁
- 英文论文作者：Xiaojun Zhou ; Fan Wang ; Department of Chemistry ; University of Si Chuan
- 年：2016
- 作者机构：四川大学原子与分子物理研究所;
- 论文关键词：氢提取反应 ; 势垒高度 ; DMC方法
- 英文论文关键词：hydrogen-transfer reactions ; barrier height ; DMC method
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第十八分会：电子结构理论方法的发展与应用
- 语种：中文
- 分类号：O641.1
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第十八分会 ; 电子结构理论方法的发展与应用
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：291k
- 原文格式：D
- 会议级别：全国
摘要
量子蒙特卡洛方法具有很高的并行效率,计算量随体系大小的标度较低,而且具有很高的计算精度,能用于较大体系的高精度计算。本文中,我们采用固定节面的扩散量子蒙特卡洛方法(FN-DMC)计算燃烧化学中的一类重要反应:氢提取反应的能垒高度。我们用FN-DMC计算了Trular等发展交换相关泛函时所用HTBH38/04的19个氢提取反应的正逆向势垒高度。在FN-DMC计算中采用Jastrow因子与单行列式波函数乘积形式的引导波函数。其中的单行列式波函数中的轨道分别采用全电子基组6-311+G(2d,p)以及两个不同的赝势及相应基函数,在LDA近似所得到。我们用FN-DMC计算的结果与B3LYP、M06-2X、CCSD、CCSD(T)和显相关CCSD(T)计算结果以及参考结果做了对比。计算结果显示CCSD(T)方法和显相关CCSD(T)方法得到的结果与参考结果吻合最好,而FN-DMC对这些反应的能垒高度也给出了高精度的结果:与最优势垒估计值的平均偏差为0.98kcal/mol,在化学精度以内。但是CCSD(T)由于计算量非常大,难以用于较大的分子体系,而FN-DMC可用于较大分子的氢提取反应能垒的高精度计算。
Quantum monte-carlo method can be applied to calculations of relatively large systems with high accuracy due to its high parallelization efficiency and low computational scaling.In this work, the fixed-node diffuse quantum monte-carlo(FN-DMC) is adopted to calculate barrier heights of hydrogen abstraction reactions.Forward and backward barrier heights of 19 H-abstraction reactions employed in Trular's group for developing XC functional are calculated with FN-DMC.Single Slater determinant with Jastrow factor is used as guide functions in calculations with the Slater determinant obtained from LDA calculations using all-electron 6-311+G(2d,p)or pseudopotentials and their corresponding basis functions.The calculated results are compared with those from B3 LYP, M06-2X, CCSD(T) as well as reference values.CCSD(T) results are in best agreement with reference values, while FN-DMC also affords barrier heights with an average error of 0.98kcal/mol.This result indicates that FN-DMC can be employed to calculate barrier heights of H-abstraction reactions of large molecules with high accuracy.
Quantum monte-carlo method can be applied to calculations of relatively large systems with high accuracy due to its high parallelization efficiency and low computational scaling.In this work, the fixed-node diffuse quantum monte-carlo(FN-DMC) is adopted to calculate barrier heights of hydrogen abstraction reactions.Forward and backward barrier heights of 19 H-abstraction reactions employed in Trular's group for developing XC functional are calculated with FN-DMC.Single Slater determinant with Jastrow factor is used as guide functions in calculations with the Slater determinant obtained from LDA calculations using all-electron 6-311+G(2d,p)or pseudopotentials and their corresponding basis functions.The calculated results are compared with those from B3 LYP, M06-2X, CCSD(T) as well as reference values.CCSD(T) results are in best agreement with reference values, while FN-DMC also affords barrier heights with an average error of 0.98kcal/mol.This result indicates that FN-DMC can be employed to calculate barrier heights of H-abstraction reactions of large molecules with high accuracy.
引文
[1]Manolo C.per;Kelly A.Walker;Salvy P.Russo.J.Chem.Theory Comput.2012,8,2255-2259
[2]Zhao Y,Lynch BJ,Truhlar DG.Phys.Chem.Chem.Phys.2005,7,43-52.
[2]Zhao Y,Lynch BJ,Truhlar DG.Phys.Chem.Chem.Phys.2005,7,43-52.