Setting NOISY_GAMMA for different atom kinds in SGCPMD

[Matt D]

Hi all,

I'm trying to run second generation Car-Parrinello MD (i.e. Thomas Kühne's method in Kuhne, TD; Krack, M; Mohamed, FR; Parrinello, M., PHYSICAL REVIEW LETTERS, 98 (6), 066401 (2007) ) in CP2K but using different values of NOISY_GAMMA for different species.

In Kühne's paper it suggests this is possible, but I can't seem to find the relevant keyword in the manual. I've also seen different values of NOISY_GAMMA being used in recent papers using SGCPMD, for example in work from Marcella Ianuzzi and Jun Cheng's groups (JACS Au 2021, 1, 569−577) so I believe it is possible.

So far I have tried:

NOISY_GAMMA {value1} {value2} {value 2}

and 

GAMMA_D {value1} {value2} {value3}

but CP2K version 7.1 doesn't recognise GAMMA_D as a parameter (I informally heard it used to used in earlier implementations) and NOISY_GAMMA is expected to be a single value, rather than multiple values.

If anybody can share/suggest what might be the correct syntax I'd greatly appreciate it.

Thanks.

Best wishes,

Matt

[Marcella Iannuzzi]

Hi Matt, 

You should be able to use different gammas by activating thermal regions addressing specific subsystems. 

You need a LANGEVIN section with GAMMA and a THERMAL_REGION section with DEFINE_REGION subsections, 

each of them containing a NOISY_GAMMA_REGION keyword and a LIST of particles. 

Kind regards

Marcella

[hut...@chem.uzh.ch]

Hi

you can find a couple of examples in

tests/QS/regtest-md-lgvregion/langevin_regions*

regards

Juerg
--------------------------------------------------------------
Juerg Hutter Phone : ++41 44 635 4491
Institut für Chemie C FAX : ++41 44 635 6838
Universität Zürich E-mail: hut...@chem.uzh.ch
Winterthurerstrasse 190
CH-8057 Zürich, Switzerland
---------------------------------------------------------------

-----cp...@googlegroups.com wrote: -----
To: "cp2k" <cp...@googlegroups.com>
From: "Matt D"
Sent by: cp...@googlegroups.com
Date: 07/14/2021 05:41PM
Subject: [CP2K:15739] Setting NOISY_GAMMA for different atom kinds in SGCPMD

--
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+uns...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/cp2k/10f9a3aa-d3b3-4c32-9974-e6b4d423cb52n%40googlegroups.com.

[Matt D]

Hi Marcella and Juerg,

Thanks that's perfect, I just gave it a try and have gotten it working.

Best wishes,

Matt