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lammps计算热导率过程中的问题

作者 vividly-w: 来源: 小木虫 300 6 举报帖子

我在用lammps模拟计算热导率（EMD方法），现在存在问题是NVE（温度设置在300K）过程中温度在不断地升高，或者出现的热导率为负值两种情况，不知道该怎么解决，希望有大神指导一下，万分感谢！

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iSimuLy

BruceFan说LAMMPS计算出的热导在低维下是有问题的，具体请pm他吧
brucefan

1) temperature increasing is usually caused by an insufficient equilibration using the NVT or the NPT ensemble before switching to the NVE ensemble.

2) Negative thermal conductivity is unusual and there may be a mistake in the implementation of the Green-Kubo integration in your script.
You can output the heat current data and calculate the heat current autocorrelation function (HCACF) and the running conductivity.
Use figures to analyze your results.
Check sample C codes at http://blog.sciencenet.cn/blog-3102863-983995.html
vividly-w

引用回帖:
2楼: Originally posted by iSimuLy at 2017-02-20 18:44:02
BruceFan说LAMMPS计算出的热导在低维下是有问题的，具体请pm他吧

非常感谢！
vividly-w

引用回帖:
3楼: Originally posted by brucefan at 2017-02-20 20:46:16
1) temperature increasing is usually caused by an insufficient equilibration using the NVT or the NPT ensemble before switching to the NVE ensemble.

2) Negative thermal conductivity is unusual ...

非常感谢老师，我尝试一下！
lfbdkkd

我出现了和你一样的问题请问楼主解决了吗
三岁薇恩

引用回帖:
3楼: Originally posted by brucefan at 2017-02-20 20:46:16
1) temperature increasing is usually caused by an insufficient equilibration using the NVT or the NPT ensemble before switching to the NVE ensemble.

2) Negative thermal conductivity is unusual ...

老师，请问在用MP法计算热导率时，如图输出ftc（交换能量）一列数据全为0是为什么呢？

ftc.png

，