[Pw_forum] Environ-0.2 support Born-Oppenheimer MD ?
oliviero.andreussi at usi.ch
Tue Jan 26 10:28:55 CET 2016
In the pw.x code the MD engine is indeed Born-Oppenheimer (BO). In the
cp.x code you also have Car-Parrinello and damped dynamics available. BO
in pw.x was supported from the very first version of Environ-0.1 and
from QE-5.1.X. Starting from the new releases of QE (5.3.0) and Environ
(0.2), the effects of Environ can be used also with the cp.x code and
with similar results. More info on what is supported and what is not can
be found on the project/releases webpage
Please note the following points:
- the implemented environment embedding schemes are not (yet) dynamic,
in the sense that, at any given time, they are computed on the given
charge density of the QM system, with no retardation/memory/history
effects. Thus, the dynamics performed with the continuum dielectric of
Environ will not have its true meaning, but will provide a sort of more
statistically averaged dynamics, in which at every step the solvent is
fully equilibrated with the solute. Whether this suits your applications
is hard to tell, but for sure it may provide some useful insights (and
won't cost too much, compared to an explicit solvent simulation).
- the overhead of the Environ calculation with the two codes (pw.x and
cp.x) is not the same, it is significantly smaller for the BO MD in the
PW code: the cost of computing the embedding potential is the same in
the two codes, but the cost of each electronic step is significantly
different (much smaller in cp.x).
Please let me know if the above answers are not clear enough or if you
have more doubts.
P.S. Please remind to sign with your affiliation, when asking questions
to this forum.
On 01/25/2016 04:08 PM, Yang, Chi-Ta wrote:
> Dear All,
> Sorry to ask this question. First, I would like to make sure that
> is MD in PWscf (PW) Born-Oppenheimer MD ? Does Environ-0.2 support
> this MD?
> Thanks a lot,
> Pw_forum mailing list
> Pw_forum at pwscf.org
Senior Postdoctoral Researcher
École Polytechnique Fédérale de Lausanne (EPFL) and
Università della Svizzera Italiana (USI) of Lugano
USI Campus, Via G. Buffi 17, 6904 Lugano, Switzerland
Emails: oliviero.andreussi @ epfl.ch -or- usi.ch
Tel: +41-(0)58-666-4810 / Skype: olivieroandreussi
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