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how to identify the twin structure in FCC and BCC crystals using Ovito?

Dear Ovito developers,

I am working on identifying the twin structure in FCC and BCC crystals.  Could you please tell me how I can identify the twin structure in FCC and BCC crystals using Ovito?  According to the work of someone, in FCC structure,  a single hexagonal-close-packed (HCP) coordinated-layer represents a coherent twin boundary (TB), as shown in the attached figure, where atoms are colored using CNA values.  What about BCC crystal?

 

sincerely yours,

Xiangkai

Uploaded files:
  • FCC.png

Dear Xiangkai,

Yes, in FCC crystals, coherent twin boundaries appear as mono-atomic layers of HCP-like atoms. You can identify them in OVITO quite easily and directly using the standard crystal structure identification functions (e.g. Common Neighbor Analysis (CNA) or Polyhedral Template Matching (PTM)).

For BCC crystals, I can refer you to this work (DOI 10.1016/j.mex.2016.03.013):

http://jomoeller.github.io/bda/

The author developed a BCC defect analysis algorithm on the basis of OVITO's basic capabilities, which allows identifying twin boundary structures and other prominent defect types in BCC crystals.

-Alex

Dear Alex,

Thanks for such detailed reply! It is really helpful.

Today, I read some papers in which the authors mentioned the Crystal Analysis Tool  when analyzing the defects structure.  It seems that the twin structure in both FCC and BCC structures can be determined by this  software.

Best wishes,

Xiangkai