Hi Anuj,

1)

Both the Elastic Strain Calculation and the PTM modifier can compute the atomic elastic deformation gradient tensor F. This is, if I remember correctly, the inverse-transpose of the

*lattice correspondence tensor* G mentioned in the original publication of Hartley and Mishin [Acta Materialia 53 (2005) 1313]. The Nye tensor is the negative curl of this G tensor, which must be calculated using a finite differences scheme. OVITO doesn't do this last step for you, sorry.

2)

I think you didn't copy/paste the complete script from the

example page. The implementation of the

*modify()* function in your screenshot is obviously incomplete.

-Alex