The ABINIT Users Mailing List ( CLOSED )

[verstraete@pcpm.ucl.ac.be]

What you're looking for is strtarget

http://www.abinit.org/ABINIT/Infos_v4.4/varrlx.html#strtarget

Which does exactly what you want. You fix a diagonal stress tensor with 
1/3 pressure along the diagonal and you relax normally (ionmov 2 + optcell 
2)

Be careful with convergence. Precise stresses need very well converged 
calculations. GPa errors are easy to come by.

Matthieu


On Wed, 27 Oct 2004 verissim@df.ufscar.br wrote:

> Hi abinit users,
>
> I'm a new user to abinit. I am performing convergence studies for BaO, 
> and so far things seem to be going ok. My next step would be to study 
> this system under pressure in two allotropic forms. The first one would 
> be easy to do: applying pressure to a NaCl structure just changing the 
> lattice parameter would do the job. However, the second allotropic form 
> displays a non-uniform response along the translation vectors. I would 
> like to know if there is an option to perform structural optimizations 
> of the axes and atomic positions, but specifying a final pressure. For 
> example, I would like abinit to determine the translation vectors of the 
> second allotropic form, but under a hydrostatic pressure of, say, 5 GPa.
>
> Any help would be greatly appreciated...
>
> Regards,
>
> Marcos

--
===================================================================
Matthieu Verstraete               mailto:verstraete@pcpm.ucl.ac.be 
PCPM, Boltzmann, pl. Croix du Sud, 1            tel: 010/ 47 33 59
B-1348 Louvain-la-Neuve  Belgium                fax: 010/ 47 34 52