which configuration is reasonable?

[lknife]

Dear experts,

I built an interface using "Interface" plugin. However, after the geometry optimization, it resulted in a strange interface configuration (please see attached files), is it reasonable?
The settings for the Calculator and geometry optimization blocks are:

(1) Calculator: GGA-OMX-high,  k_point_sampling=(1, 9, 9), density_mesh_cutoff=200.0*Hartree
(2) Geometry optimization: max_forces=0.01*eV/Ang, max_stress=0.001*eV/Ang**3, disable_stress=True (constrain cell x, y, z)

Thanks very much for anyone who is willing to help me！Thank you for your time and kind help!

lknife

[lknife]

Sorry, the question should be: is the optimized interface configuration reasonable?

[Anders Blom]

That is not an interface, it's a periodic supercell

[lknife]

This job is to create an in-plane interface between Td-WTe2 and 1H-WTe2 monolayer. You can see that the left part of the unit cell is different with the right part . It's a super cell. But it's also an interface, I think. After matching the two monolayers, I wanted to relax the interface. However, the results showed me a strange configuration. I don't know if it is reasonable. 

[lknife]

For this interface configuration, it's periodic along B direction, semi-periodic along C direction and non-periodic along A direction.
When doing the geometry optimization of the interface, how to set the boundary conditions in Poison solver?

[Anders Blom]

The structure is set up as periodic in C also, and that's the problem. I refer to the many tutorials on transport systems

[lknife]

Thank you for your comment. Then could you please tell me how to set the boundary condition for this interface configuration when doing the geometry optimization?

[Anders Blom]

It's all in the tutorials, see e.g. http://docs.quantumwise.com/tutorials/device_relaxation/device_relaxation.html

[lknife]

Thank you very much! I am now reading this tutorial although I have read this tutorial before. I need to restudy it thoroughly.