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标题: CP2K与VASP中Nosé-Hoover chain thermostat关键词的对应问题 [打印本页]

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Author: wth1219 时间: 2024-1-29 06:50
标题: CP2K与VASP中Nosé-Hoover chain thermostat关键词的对应问题
本帖最后由 wth1219 于 2024-1-29 06:55 编辑

如题。CP2K中Nosé-Hoover chain thermostat需要以下四个关键词：
LENGTH: length of the Nose-Hoover chain.
TIMECON: timeconstant of the thermostat chain.
MTS: number of multiple timesteps to be used for the NoseHoover chain.
YOSHIDA: order of the yoshida integrator used for the thermostat.

VASP中Nosé-Hoover chain thermostat的关键词同样有四个：
NHC_NCHAINS: Length of the Nosé-Hoover chain.
NHC_PERIOD: Time scale of the Nosé-Hoover chain in terms of the number of MD steps.
NHC_NRESPA: The number of subdivisions of the integration step used in propagation of thermostat variables in Nosé-Hoover-chain (NHC) thermostat.
NHC_NS: The number of subdivisions of each RESPA step used in the integration step used in propagation of thermostat variables in Nosé-Hoover-chain (NHC) thermostat.

不知MTS（CP2K）与NHC_NRESPA（VASP）两个关键词的含义是否相同？（两组中其余三个关键词显然可以一一对应。）

另外，根据VASP wiki中NHC_PERIOD关键词的Tip (The value of NHC_PERIOD should correspond to a characteristic time scale in the system. If this is unknown, NHC_PERIOD should be set to a value between 20 and 200.)，以FPMD常用的时间步长1 fs计算，HC_PERIOD的取值范围为20 fs ~ 200 fs、默认值只有40 fs，而CP2K中TIMECON的默认值为1000 fs，不知二者差距为何如此巨大、如何设置比较合适？

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