Hello!
Sincere blessings to you
I am currently conducting a nanoindentation simulation in an NVT environment, but the resulting force curve fluctuates greatly. I tried to adjust the value of Tdamp, but following the manual’s advice and using 100 time steps, the resulting force curve still fluctuated greatly.
Therefore, I would like to ask everyone, what value should Tdamp use? Is the fluctuation of the force curve also related to other aspects?
The attachment is one of my input files
Blockquote
Thanks again
Sorry,because I’m a new user，I can‘t upload my input file
You can still copy past inputs and use the preformated text option to make them readable. In any case, you also have to read the forum guidelines and make sure that your post respects the rules.
Simon
That is what forces do at the atomic level.
The choice of Tdamp and the fluctuation of forces are two very different issues.
You cannot treat behavior at the atomic level like you would do for macroscopic systems. The discipline that links the atomic level with the macroscopic level is called statistical mechanics. If you want to do meaningful MD simulations and understand your observations, I suggest you get a suitable text book and study it or enroll in a corresponding class.
Broadly speaking when applied to atomic MD data this usually translates that one either has to average over the ensemble of atoms or over time (but only in case the system is in equilibrium) to reduce the fluctuation of observables. You can find numerous of such discussions in the archives over fluctuations of temperature and pressure. Since temperature is linked to the velocity of atoms and pressure to the force on atoms, most of the statements about the latter also apply to forces.