求助hindered rotor的Pitzer-Gwinn处理

无聊挂机

在论文上看到“The hindered rotor option in Gaussian16 is used to compute this effect using the Pitzer-Gwinn option.”
其中hindered rotor倒是明白用freq=hinderedrotor，但是pitzer-gwinn并不了解，请问这个怎么处理？标的参考文献是篇1942年的论文：Energy Levels and Thermodynamic Functions for Molecules with Internal Rotation I. Rigid Frame with Attached Tops

sobereva

如置顶的新社员必读贴和论坛首页的公告栏所示，求助帖必须在帖子标题明确体现出此帖内容是求助或提问，并反映出帖子具体内容，避免有任何歧义，仔细看http://bbs.keinsci.com/thread-9348-1-1.html。我已把你的不恰当标题“hindered rotor。”改了，以后务必注意，下次违规将删帖+扣分+记违规处理。

sobereva

freq=hinderedrotor输出信息里有这样的内容
取Pitzer & Gwinn那一列

无聊挂机

sobereva 发表于 2021-3-4 22:31
freq=hinderedrotor输出信息里有这样的内容
取Pitzer & Gwinn那一列

谢谢老师！请问如果测-OH的转动势的话，能不能在freq=hindererdrotor的时候也点上anharmonic呢？

sobereva

无聊挂机 发表于 2021-3-5 11:43
谢谢老师！请问如果测-OH的转动势的话，能不能在freq=hindererdrotor的时候也点上anharmonic呢？

语义不明
获得转动势曲线应当通过柔性扫描二面角实现
详谈使用Gaussian做势能面扫描
http://sobereva.com/474（http://bbs.keinsci.com/thread-12660-1-1.html）

量化小菜鸡

sobereva 发表于 2021-3-4 22:31
freq=hinderedrotor输出信息里有这样的内容
取Pitzer & Gwinn那一列

请问社长，这三种方法给的hindered rotor矫正有正有负。有没有哪一种方法是比较推荐的？

sobereva

量化小菜鸡 发表于 2021-3-6 08:44
请问社长，这三种方法给的hindered rotor矫正有正有负。有没有哪一种方法是比较推荐的？

很久以前用过，现在细节想不起来了，具体可以看Gaussian自动考虑受阻转子的介绍文章JCP,108,2314

量化小菜鸡

sobereva 发表于 2021-3-7 05:42
很久以前用过，现在细节想不起来了，具体可以看Gaussian自动考虑受阻转子的介绍文章JCP,108,2314

谢谢社长，我去看看那篇文章。

糖糖糖豆9988

sobereva 发表于 2021-3-4 22:31
freq=hinderedrotor输出信息里有这样的内容
取Pitzer & Gwinn那一列

2.2. Master equation calculations
For these reactions with pronounced transition states, the conventional transition state theory was used to predict rate constants. Most vibrational modes were treated according to the harmonic oscillator approximation. Some low-frequency vibrational modes corresponding to internal rotations were processed into one-dimensional hindered internal rotors, and the hindered potential functions were attained by a relaxed scan with 10 ° steps at the B3L YP/6-311 ++ G(d,p) level with Master Equation System Solver (MESS). Pitzer-Gwinn corrections have been used. For the entrance channel without barriers, we used the microcanonical variational transition state theory which usually refers to energy-resolved rate constants。
请教sob老师，①这段描述里考虑的“ Pitzer-Gwinn corrections”是不是等价于您回复的在高斯里采用关键词“freq=hinderedrotor”，然后在输出文件里取相应的Pitzer-Gwinn列？②这一列是不是就是频率值呢？

sobereva

糖糖糖豆9988 发表于 2022-9-14 15:17
2.2. Master equation calculations
For these reactions with pronounced transition states, the con ...

不完全一样。freq=hinderedrotor并不会做扭转势的扫描。具体看Gaussian里的hinderedrotor功能对应的原文