[Pw_forum] on optimize amorphous structure

[Matteo Cococcioni]

Dear Li

I totally agree with what Jean-Yves suggested. To realize how far your
structure is from equilibrium a simple thing to do is
looking at forces and stresses you can compute at the end of a scf run.
Then, on the base of these results you will decide what to do.

Matteo



li niu wrote:
> Dear Jean-Yves Raty,
>
> Thanks for your help!
> I don't know if I express myself clearly. I use a model structure,
> generated by CPMD. This model contains 64 atoms in a periodically
> repeated cubic cell, at the experimental density. The electric
> structure and optical properties have been previously calculated for
> the same model structure.
> I want to calculate vibrational properties for the same structure. In
> this case, need I optimize this structure ? If the answer is yes, do I
> use the relax, vc-relax or others?
> Thanks!
>
> Best!
> Niu Li
>
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