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Re: [lammps-users] [EXTERNAL] hi about the potential parameters of latte
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Re: [lammps-users] [EXTERNAL] hi about the potential parameters of latte

From: "Goldman, Nir" <goldman14@...87...>
Date: Thu, 19 Oct 2017 13:52:05 +0000

Hi All,


To follow up, regarding DFTB+/LAMMPS, Steve is correct: in this case, DFTB+ is the driver. It calls LAMMPS as a library, which then “calls back” to DFTB+ each time step to pass in coordinates and lattice vectors and then receive the system forces and components of the stress tensor. I had to make some modifications to the DFTB+ code, which I would be happy to share with any interested parties.


Regarding a comparison of DFTB+ and LATTE, both are very similar in spirit as both are derived from a density functional tight binding formalism. I’ve never used LATTE, so I can’t comment on it, specifically. However, I would caution any potential user to thoroughly test either code to assess its accuracy and computational efficiency for a given system of interest. Density functional tight binding is a semi-empirical formalism, so there’s no guarantee that an off the shelf parameterization will yield usable results.   


Hope that helps,





Nir Goldman

Material Sciences Division, PLS

Lawrence Livermore National Laboratory

P.O. Box 808, L-282

Livermore, CA 94551-0808

Phone: (925) 422-3994


From: Steve Plimpton <sjplimp@...24...>
Date: Wednesday, October 18, 2017 at 9:14 AM
To: Oleg Sergeev <seoman@...567...>
Cc: Steve Plimpton <sjplimp@...3...>, "Song, Zhigong" <zhigong_song@...802...>, "cawkwell@...795..." <cawkwell@...795...>, "cnegre@...795..." <cnegre@...795...>, "" <>, "Goldman, Nir" <goldman14@...87...>
Subject: Re: [lammps-users] [EXTERNAL] hi about the potential parameters of latte


I'll leave comparisons of LATTE and DFTB+ to the experts.

I'm CCing Nir Goldman (LLNL) who has coupled DFTB+ and LAMMPS

for modeling he has done.  I believe what he did was add

some code to DFTB+ to call LAMMPS as a library.  I'm not clear on

if that version of DFTB+ is publicly available - Nir can comment.

From a software point of view the coupling of LAMMPS to the 2

codes is the inverse of each other, though both accomplish the

same thing,

For LATTE, LAMMPS is the driver, if calls LATTE as a lib each timestep,

thru fix latte as a wrapper.  It passes coords, and receives back forces.

For DFTB+, it is the driver, it calls LAMMPS as a library, and the

LAMMPS script that is run includes a fix external command, which does a callback

to DFTB+ each timestep to pass coords and receive back forces.

Nir added a new Fortran interface to the LAMMPS lib to facilitate

this - see examples/COUPLE/fortran_dftb.




On Mon, Oct 16, 2017 at 11:44 AM, Oleg Sergeev <seoman@...567...> wrote:

Dear Zhigong,


I believe there are also parameter files for MgO. Don't know if those are of interest to you.


And I also have another question of, I think, general interest to other users. As far as I know, while the LATTE interface is new, LAMMPS can be and in the past was already used with DFTB+ code for running TB simulations. From the user point of view, what are the main advantages of one code over the other?





16.10.2017, 20:00, "Steve Plimpton" <sjplimp@...3...>:

Hi - Marc and Christian are the right folks to answer this,
as it's really a LATTE Q. I'm also CCing this to
the LAMMPS mail list, as I think the Q/A will be of
general interest to other LAMMPS users who want
to try out tight-binding and LATTE.

Marc/Christian - if you CC the mail list address
in your replies, the info should appear there as well.



 From: "Song, Zhigong" <zhigong_song@...802...>
 Date: Sat, 14 Oct 2017 15:19:05 -0400
 Cc: cnegre@...795..., sjplimp@...3...
 Content-Type: multipart/alternative; boundary="001a113b0cc89a18ad055b86a52b"

 [1:text/plain Hide]
 This is a heavy lammps users from Brown University. I am very excited to
 find that tight-binding method is implemented with lammps and make it
 complie successfully. However, when I finished the testing in example
 directory, I realized that there are only C,H,N,O potentials within. I am
 forced on mechanical properties of materials Thus, I am just wondering if
 there are TB potentials of other elements. Or where could I get them?
 Thanks a lot for all your contributions on it,

 [2:text/html Show]

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