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Crystal Orientation

Hi Ovito Users,

I simulated the solidification process of stainless steel using LAMMPS software. After solidification, the polycrystalline structure was created in the simulation box. I need to detect the direction and the miller indices of the planes in each crystallite. I can see the different crystal orientation using polyhedral template matching modifier and colour-coding. My question is how can I detect the indices of the specific planes in each crystallite and also specific direction.

Kind regards,


Dear Mehran,

We are trying to understand your question. Could you please explain more precisely what you mean with "planes in each crystallite". What is known about these planes? How are they defined?

Typically, one either knows the miller indices or the normal vector of a crystal plane. Given the crystal orientation in the simulation coordinate system, it is then possible to compute the other. It doesn't become clear from your description what is the known input and what is the expected output of the calculation you have in mind.

PTM computes a local crystal orientation, which can be used to translate direction vectors from the crystal lattice frame to the simulation coordinate system. Thus, you could use this orientation information to translate miller indices into spatial vectors in the simulation coordinate system. Please see the docs page of the PTM modifier. It specifies how the reference crystal lattice frame is oriented for each crystal structure type.

Best regards,