Fix deposit temperature increases wildly

LAMMPS LAMMPS Beginners
1

Hello,

I’m using fix deposit to add atoms to a surface,the substrate was divided by three slabs along the z-axis. The bottom slab was fixed and the middle one was in an NVT ensemble. And the top one was in an NVE ensemble. For the NVT ensemble its temperature was set at 1000 K. I found the temperature suddenly increased wildly.

I attached the input file
jj.in (1.7 KB)

Best regard

2

When does it start to increase wildly, and by how much? Did you visualize the dump file? You might find that your bottom layer is not actually fixed…

Unrelated, but you should undump your first dump command before you start your second, or you’ll be outputting the same data to both files in the second run.

3

Hello,
it start to increase wildly after 1000000 step

4

Please address all the questions that have been asked to you. People are trying to help you (for free!) here, but they wont help you for long if you just ignore 2 questions out of 3 as if they were never asked.

Concerning your input, I see several issues:

  • temp/rescale is not a recommended choice, as commented many times on this forum
  • you are applying a thermostat on a subgroup of atoms without using the fix_modify command
  • you are not using the compute_modify dynamic yes, while having a fluctuating number of atoms in the system