Optimize Geometry in Device Configuration

[395235863]

What are the detailed differents between Optimize Geometry in Device Configuration and Optimize Geometry in Bulk Configuration?

Thank you very much!

[Jess Wellendorff]

The difference is small:
- force minimization works very well for both bulks and devices, but for devices the electrode extension regions (and electrodes, of course) are fixed.
- stress minimization (lattice vector optimization) works very well for bulks, and is also possible for devices, but for devices the stress tensor may not be accurately computed, so we recommend in general to not use it for devices (i.e. only minimize forces). However, a procedure for optimizing the length of the central region in devices does exist, see http://docs.quantumwise.com/tutorials/device_relaxation/device_relaxation.html.