Dear all,

I was tasking elastic constants in CASTEP.

I have little acquaintance with setup tab of elastic constants.

I want to know What Red box means ?

(meaning of (1 0 0 1 0 0) and why enter the (1 0 0 1 0 0) ?)

And If It has above same system, what kind of strain does system have ?

(I think that it has below strain pattern,

                                                        aa     0      0

                                                          0     0    aa

                                                          0    aa     0

but It isn`t like this)

Can anyone give me a hint how to understand that property ?

many thanks,

Lim