[DFTB-Plus-User] DFTB+ 20.2 released

[Carlo Nervi]

Dear Bálint, and all dftb+ developers,
thank you very much for the efforts! I really appreciate it.
I'd like to contribute for what concerns the solid state systems, periodic
calculations, and in particular the MBD and TS treatment of weak
interaction, pulling out a problem that I was mentioning in the recent
"Calculation of Kpoints" thread. The problem arises whenever a periodic
cell containing several atoms is computed for geometry optimization.
I started with the development version of dftb+, and I also tested the last
20.2 stable release. Up to now I found the following problems:

First of all I'm working with relatively large periodic systems. I tested
on 128 atoms per unit cell.
D4 works apparently smoothly (setting s9=0), with relative fast
calculations, as expected.
MBD is very slow, but TS is extremely slow.
The average time requested to perform a single geometry step in D4 is
around 0.55 s, in MBD is 9.4 s, but in TS is 732 s.
This makes no sense to me. TS should cost approximately as D4, as far as I
know.

Are there any library problems? I'm using openblas 0.3.12, openmpi and I
set OMP_NUM_THREADS=1 to avoid OpenMP.

Other programs run fine in parallel (Quantum Espresso for instance for
openmpi and Gaussian16 for OpenMP).
Thank you for your time,
Carlo


Il giorno mer 18 nov 2020 alle ore 11:38 Bálint Aradi <aradi at uni-bremen.de>
ha scritto:

> Dear DFTB+ community,
>
> We are pleased to announce the next stable version (Release 20.2).
> Thanks to the work of those contributing to the code, this version again
> contains several major improvements. These include
>
> * Many body and Tkatchenko-Scheffler dispersion models
>
> * Delta DFTB for the lowest singlet excitated state of closed shell systems
>
> * Electron transport for system with (colinear) spin polarisation, plus
> Green's function embedding for the surfaces of magnetic systems
>
> * A new code for phonon transport calculations
>
> * Linear response excited state forces for spin polarised systems
>
> * The FIRE geometry optimiser and improvements to the LBFGS optimiser
>
> For further details and to download, please visit the release page:
>
> http://www.dftbplus.org/download/dftb-stable/
>
> We would like to thank you for all your feedback and contributions
> which shaped this release. We hope you will find DFTB+ 20.2 useful
> for your scientific work and are looking forward to further comments,
> suggestions and contributions in the future.
>
>
> The DFTB+ developers
>
>
> Ps. Please also look out for news about the upcoming release of our
> Slater-Koster generation tools in the next weeks.
>
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>


-- 

------------------------------------------------------------
Prof. Carlo Nervi carlo.nervi at unito.it  Tel:+39 0116707507/8
Fax: +39 0116707855      -      Dipartimento di Chimica, via
P. Giuria 7, 10125 Torino, Italy.    http://lem.ch.unito.it/

*ICCC2020 has been postponed at 2022*

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International Conference on Coordination Chemistry (ICCC 2022)
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