Author Topic: Geometry Optimization  (Read 2674 times)

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Offline atk_user

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Geometry Optimization
« on: February 27, 2014, 13:16 »
Dear all,

I am try to calculate the Al unit cell with OptimizeGeometry.
However, the geometry is not changed... (Lattice parameters)
I did not consider Constrain cell and Optimizer Method is QuasiNewton, PBE functional, and DZP basis sets.

I don't know what's the problem. Could you help me?

 

Offline Umberto Martinez

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Re: Geometry Optimization
« Reply #1 on: February 27, 2014, 13:38 »
can you provide your python input script?

Offline atk_user

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Re: Geometry Optimization
« Reply #2 on: February 28, 2014, 02:56 »
Here's the input file you asked me to send you.

Thank you for your help.
« Last Edit: February 28, 2014, 02:57 by atk_user »

Offline Umberto Martinez

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Re: Geometry Optimization
« Reply #3 on: February 28, 2014, 15:42 »
There is nothing wrong with your calculations, the job finished because it reached all the convergence criteria you set. In particular the maximum stress criteria of 0.01 eV/Å**3. You can check it if you include the Stress analysis in the calculation:
Code
+------------------------------------------------------------------------------+
| Stress Report                                                                |
+------------------------------------------------------------------------------+
| [[  9.05881942e-03   5.25907270e-31   7.88860905e-31]                        |
|  [  7.89246091e-31   9.05881942e-03   5.25907270e-31]                        |
|  [  5.26356654e-31   6.57319890e-31   9.05881942e-03]] eV/Ang**3             |
+------------------------------------------------------------------------------+
You should use a much lower value, something like 0.001 eV/Å**3. See for example here this section: http://quantumwise.com/publications/tutorials/mini-tutorials/244#h3-setting-up-the-bulk-configurations

Offline atk_user

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Re: Geometry Optimization
« Reply #4 on: February 28, 2014, 15:54 »
Thank you Martinez. I'll try with your suggestion.
Thank you for your help again.  :)

Have a good day.