optimization of amorphous al2o3 structure

[HIMANI]

We have obtained the amorphous structure of Al2O3 according to your tutorial "generating amorphous structure". We have optimized this structure to make it stable. But it is taking very much time in optimization. The simulation started on 5th feb and it is still running. I have  attached the log file of simulation, please check it and tell how much more time it will take?
 We are using desktop PC with i7 configuration, 12 GB ram and 64 bit operating system.

[Umberto Martinez]

Hard to say from a log file without the input files.
As stated there DFT calculations are pretty time consuming. Are you running in parallel? you will gain a lot by doing so.

PS please update to 2014.2
http://quantumwise.com/publications/quantumwise-news/item/851-update-vnl-atk-2014-2-released

[HIMANI]

Here is the input file of the of the concerned problem.

[Umberto Martinez]

Unfortunately I suggest you to kill your job and restart by considering the following:
- 15x15x15 k-point sampling is way to much. Given the unit cell size, even running with only the Gamma is probably enough (1x1x1).
At least for a first optimization. You can increase a little bit the mesh afterwards to check the convergence.
- Not sure why you modified the default mesh cut-off. I would rather keep the default value instead of increasing k-point as you did.
- trajectory_filename='al2o3_300k_optimisedgeo' this is the same filename of your inupt file. Better to change one of the two to avoid bad surprises.
- start with a SZP basisset for silicon as the tutorial suggests. Again you can check afterwards or on a smaller system a DZP basis set.

[HIMANI]

Thank you sir!!