[Pw_forum] General discussion- Is Quantum espresso good for High Pressure work

[Nicola Marzari]

We had studied this for aluminum, and standard pseudos (3 in the valence)
were starting to fail at around 1.2 TPa:
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.77.172102

This cannot be generalized, but one could always try to see if having more
electrons moved from the core to the valence makes a difference or not.

Bottom line - if you are interested in high-pressure work, you need to learn
more re pseudopotential/PAW generation.

			nicola


On 06/03/2016 05:03, Lazaro Calderin wrote:
> Dear Raj Kamal,
>
> The answer is 'it depends'. Any code based on pseudopotentials or PAW
> data sets will start giving wrong results and/or failing in the limit of
> high pressure. The reason being that the frozen core approximation
> becomes invalid due to the cores coming too close toguether or
> overlaping with each other  (you may get away by using smaller cores),
> which btw should be preceeded by a break down of the two-center
> approximation used with PAW data sets. So, if the range of pressure of
> interest does not cause the atoms to get too close then everything
> should be fine.
>
> Best,
> Lazaro Calderin
> ====================
> Quantum Theory Project
> Deparment of Physics
> University of Florida
>
>
> On Sat, Mar 5, 2016 at 4:21 AM, Raj kamal <rajkamalloyola at gmail.com
> <mailto:rajkamalloyola at gmail.com>> wrote:
>
>
>     Dear QE experts,
>     how QE is good for high pressure work and have anyone done this High
>     pressure work using Quantum espresso.
>     --
>     /Best regards,/
>     /Rajkamal.A./
>     /Research Scholar,(SRM UNIV)./
>
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-- 
----------------------------------------------------------------------
Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL
Director, National Centre for Competence in Research NCCR MARVEL, EPFL
http://theossrv1.epfl.ch/Main/Contact http://nccr-marvel.ch/en/project