Opeb Access - Tutorial Review -
The devil in the details: A tutorial review on some undervalued aspects of density functional theory calculations

Density functional theory (DFT) has become ubiquitous for chemical applications in research and in education. The exact functional at the foundation of DFT is unfortunately unknown, and issues arise when choosing an approximation for a specific application. With this tutorial review, we tackle the selection problem and many related ones, such as the choices of a basis set and of an integration grid, that are often overlooked by occasional practitioners and by more experienced users as well. We offer a practical approach in the form of a commented notebook containing 12 experiences that can be run on a simple computer in just a few hours. We propose this review as a primary source for those who are willing to include DFT in their everyday research or teaching activities in a way that reflects the research advances of the field in the last couple of decades.

https://onlinelibrary.wiley.com/doi/10.1002/qua.26332

Physicists detect a new type of molecular bond – Physics World
https://physicsworld.com/a/physicists-detect-a-new-type-of-molecular-bond/

Virtual Winter School on Computational Chemistry - Africa Edition
Date: 05.08.2022
Time: 09:00 - 18:30 CEST

In association with VCCA-2022 the organising committee of the Virtual Winter School on Computational Chemistry will be holding a one-day satellite symposium on Friday August 5. This one-day event will be hosted in the VWSCC's space, kindly sponsored by Gather, and will be a condensed version of our annual VWSCC event, focusing on showcasing African science to the rest of the world. Since 2015 through VWSCC we have endeavoured to bring our speakers to the rest of the world virtually. In this event we hope the global community will come to see what is happening in Africa. The day will be a mixture of invited talks, poster presentations and panel discussions on topics such as getting jobs, forming collaborations, computing resources, education…

The format of the day (in CEST/CAT) will be:
09:00 - 12:00 Invited talks - more information coming soon
Break
14:00 - 15.30 Panel discussion sessions - more information coming soon
Break
17:00 - 18:30 Single-Figure Presentations

SFPs (single figure presentations) submissions are particularly encouraged from researchers working at African institutions, especially students. You will be given the opportunity to give a flash presentation of your work in our virtual poster room and mingle with other attendees. There will be prizes of speaking slots at the next edition of the Virtual Winter School.

Everyone is welcome to participate and we hope to see representation from as many countries as possible.

Registration is free, but mandatory. Read more end register here: https://winterschool.cc/africa-calling

Potential energy surfaces of water mapped for the first time
https://phys.org/news/2022-07-potential-energy-surfaces.html

A celebrated AI has learned a new trick: How to do chemistry
https://phys.org/news/2022-06-celebrated-ai-chemistry.html

CP2K v2022.1 is available

CP2K is the popular quantum chemistry and solid state physics software package. And, yes, it changed the numbering scheme.

* Migrate tensor operations to new sparse matrix library DBM (#1863)
* Add HIP support for PW (#1864)
* Drop support for GCC 5 (#1878)
* Add GAPW Voronoi integration (#1919)
* Remove deprecated sections LIBXC and KE_LIBXC (#1921)
* Add LibXC equivalents to ADMM exchange potentials (#1972)
* Improve support for metaGGA functionals (#1974)
* Use SPLA for offloading dgemm on GPUs in the mp2 module (#1951)
* TDDFT: enable state following using transition charge finger print (#1991)
* Add barostat for frozen atoms in absolute coordinate (#2000)
* Fix linkage of COSMA (#2021)
* Migrate to centralized __OFFLOAD_CUDA/HIP flags (#2027)
* Add low-scaling SOS-Laplace MP2 forces (#2031)
* Refactoring of basis set optimization code (#2068)
* Add k-points for the GW self-energy (#2073)
* CDFT: forces based on Hirshfeld partitioning (#2111)
* RPA: Add low-scaling gradients (#2131)
* MP2: Add more solvers (#2142)
* GW: Add 4-center Hartree-Fock and ADMM for exchange self-energy (#2145)
* Print vibrational modes for Newton-X (#2146)
* Add partially occupied Wannier states (#2154)
* Add GAPW_XC for TDDFPT energies (#2178)

https://github.com/cp2k/cp2k/releases/tag/v2022.1

Open Access - Completing density functional theory by machine learning hidden messages from molecules
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Kohn–Sham density functional theory (DFT) is the basis of modern computational approaches to electronic structures. Their accuracy heavily relies on the exchange-correlation energy functional, which encapsulates electron–electron interaction beyond the classical model. As its universal form remains undiscovered, approximated functionals constructed with heuristic approaches are used for practical studies. However, there are problems in their accuracy and transferability, while any systematic approach to improve them is yet obscure. In this study, we demonstrate that the functional can be systematically constructed using accurate density distributions and energies in reference molecules via machine learning. Surprisingly, a trial functional machine learned from only a few molecules is already applicable to hundreds of molecules comprising various first- and second-row elements with the same accuracy as the standard functionals. This is achieved by relating density and energy using a flexible feed-forward neural network, which allows us to take a functional derivative via the back-propagation algorithm. In addition, simply by introducing a nonlocal density denoscriptor, the nonlocal effect is included to improve accuracy, which has hitherto been impractical. Our approach thus will help enrich the DFT framework by utilizing the rapidly advancing machine-learning technique.

https://www.nature.com/articles/s41524-020-0310-0

xtb version 6.5.1 is out
* Fixes for Windows build (#629)
* Allow finding of installed test-drive dependencies (#633)
* Calculate number of electrons before restart (#638)
* Copy number of bonds for writing (#637)
* Declare optional arguments in C-API (#636)
* Fix MKL finding with Intel 2021 and newer (#640)
* Added rr-ho interpolation for heat capacity in thermo module (#644)
* Turn off GFN-FF fragmentation if it is not needed (#654)
* Make c-api example MSVC compatible (#648)
* Fixes Orca sanity check (#658)
* Resolve out-of-bounds access in ONIOM (#661)

https://github.com/grimme-lab/xtb/releases/tag/v6.5.1

Chemists change the bonds between atoms in a single molecule for the first time
https://phys.org/news/2022-07-chemists-bonds-atoms-molecule.html

Rational Density Functional Selection Using Game Theory

Theoretical chemistry has a paradox of choice due to the availability of a myriad of density functionals and basis sets. Traditionally, a particular density functional is chosen on the basis of the level of user expertise (i.e., subjective experiences). Herein we circumvent the user-centric selection procedure by describing a novel approach for objectively selecting a particular functional for a given application. We achieve this by employing game theory to identify optimal functional/basis set combinations. A three-player (accuracy, complexity, and similarity) game is devised, through which Nash equilibrium solutions can be obtained. This approach has the advantage that results can be systematically improved by enlarging the underlying knowledge base, and the deterministic selection procedure mathematically justifies the density functional and basis set selections.

https://pubs.acs.org/doi/10.1021/acs.jcim.7b00542

A gentle introduction to DFT calculations
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Density-functional theory has become a very popular and very powerful approach to the calculation from first-principles of the properties of molecules and materials. In these three talks, Nicola Marzari provides a gentle introduction 1) to the fundamentals of density-functional theory, 2) to the calculations that can be done with modern, open-source codes such as Quantum ESPRESSO, and 3) to its capabilities and limits. A typical target audience would be scientists (e.g. experimental colleagues) that want to learn more about what is possible and what is good for this kind of calculations (and what is not possible, and what is not good).

The second talk is complemented by a simple tutorial that can be done on any desktop or personal computer, independently of the operating system used (e.g. Windows, Mac, Linux), thanks to the Quantum Mobile virtual machine (for this tutorial we use the release 20.03.1). All the tutorial material is available on Github.

https://www.materialscloud.org/learn/sections/VNL7RL/a-gentle-introduction-to-dft-calculations-april-2020

Q-Chem 6.0 was just released!!

It is not free/open source but, wow, what an amazing software!
Read more about all the new features here: https://q-chem.com/support/releaselog60/

Frontier molecular orbitalets

A recent article in Chemistry World caught my attention. It reported the recent work by Yang and co-workers on describing chemical reactivity with so-called orbitalets. Orbitalets are a type of localized molecular orbital that came out of the Yang group's work on eliminating the delocalization error from density functionals. The highest occupied orbitalet is called the HOMOL, and the lowest unoccupied orbitalet is called the LUMOL.

Orbitalets can be seen as an intermediate between the fully delocalized canonical molecular orbitals (CMOs) and fully localized orbitals (LOs). As such, their energies are fairly close to the CMOs, while their localized character allows easier interpretation of reactivity in terms of frontier molecular orbital theory (FMO). Regular localization schemes like Foster-Boys, Natural Bond Orbitals loose the connection to the CMO energies, and therefore the resulting LOs are more difficult to relate directly to reactivity. The orbitalets represent some type of compromise, although it remains to be seen how well they work in practice, over a large range of different compounds and reactivity patterns.

https://kjelljorner.github.io/blog/quantum_chemistry/2022/07/17/Orbitalets.html

MIT Discovers Semiconductor That Can Perform Far Better Than Silicon
https://scitechdaily.com/mit-discovers-semiconductor-that-can-perform-far-better-than-silicon/

Chemistry breakthrough offers unprecedented control over atomic bonds
https://newatlas.com/science/chemistry-breakthrough-first-control-atomic-bonds-molecule/

Could machine learning fuel a reproducibility crisis in science?
https://www.nature.com/articles/d41586-022-02035-w

A new theory of quantum subsystems
https://phys.org/news/2022-07-theory-quantum-subsystems.html