When i create a interface such as a grain boundary i follow the instructions given in the online help for "twinning in silicon" in "layer builder"

It involves choosing a cleavage plane with millers indices h k l and another with -h k l

then using " Build->Layers" and choosing these two planes as layer 1 and layer 2  and clicking "Build" we create the boundary (or interface).

However before clicking building we have to ensure than the lengths u and v are the same in layer 1 and layer 2.

In the example given in the tutorial for twinning in silicon the lengths match.

However, when i do the same for Aluminum, the lengths u and v for the two layers are interchanged.

i.e. the value for u in layer 1 is the value for v in layer 2.

Because of this i get an error. Can you give a solution for this?