Langevin Thermostat not Reaching Set Temperature

Hi Majdi,

Have to tried by changing Tdamp/damp parameter of fix Langevin ?

It is 2.0 in present script while your dt = 0.0004. I would have thought it close to

0.04-0.4 or so.


Dear Dr. Tiwari,

I have not tried varying Tdamp yet. I chose this value based on a paper from Professor Bowen Li’s research group, attached to this email.

I will reduce it to the suggested value and communicate the outcome.

Thank you,


Chen_MD-Simulations-HeatBathEffect_2010.pdf (666 KB)

Dear Dr. Tiwari,

I tried using a damping factor of 0.4; the thermostated region gets closer to the set values but the non-thermostated region becomes non-linear and irregular.

I believe the problem is actually my simulation time. I re-read the last reference carefully and found that their system is 3x3x10 unit cells and they let it reach steady-state over 40 ns. My system is 10x10x8 unit cells so the run is much much longer. I’ve setup a new simulation with a longer simulation time. I’ll let the community know of the outcome once it is in.

Thanks again for your input. I appreciate it.