Dear San Zhang as a synthetic inorganic chemist I'm absolutely no expert in this field. However, I'm just sorry to see that your interesting technical question has not yet received any qualified answers from experts. What I can strongly suggest to you is to use RG directly as a valuable source of information. You can normally find answers to virtually all technical questions by searching either the "Publications" or "Questions" sections of RG for relevant literature references or closely related questions. Quite often the same question has already been asked years ago and the answers are still useful.
For example, the following interesting article is freely available as public full text on RG:
A grain boundary formulation for crystal plasticity
Article A grain boundary formulation for crystal plasticity
Also please check this RG link:
Neper2CAE and PyCiGen: Scripts to generate polycrystals and interface elements in Abaqus
Article Neper2CAE and PyCiGen: Scripts to generate polycrystals and ...
Please note that these are just two examples of relevant research articles which are accessible though RG. I hope his helps a bit. Good luck with your work and best wishes, Frank Edelmann