the simulation of models with oxygen vacancies

Dear all,

I am trying to simulate a ABO4 material with vacancies while the models always experienced collapse of atomic layers with the expansion of volume. The results of running a supercell without defects look good and so I am sure that the FIELD is a suitable one. The CONTROL file is posted as follows:

Dear Xingyu Wang,

I think the tauP should be greater e.g. 500 or 1000. Perovskites with vacancies can result in a very fragile structure to equilibrate. If your box is free to expand a lot you can easily loose the the structure. Instead with a slow deformation the structure is better preserved.

Good luck


Try to run your structure without shell model and keep the resulting box as a starting point.
then modify your config file, to incorporate newly the shell model
(the code atomsk does the job in a very efficient way).

Then run your simulation with the shell model. If it fails, it certainly comes from a problem with the shell. If it goes too far/close, you may get unstable system. Some function exists to avoid shell going far away or too close to another or a small weight on the shell avois too big unrealistic movements.

Hoping it helps.


Dear ao and Guilhem,

Thanks so much for your reply! Let me change my settings one by one and see what happens.