Volker Blum

Thank you so much, again! That's even better! Looking forward to the next updates!

Reposting since I was really happy to see this. Thanks to everyone at @fhi-aims.bsky.social , too!

Dear Henrique, that is excellent! 🎉 THANK YOU (really brightened my day). I am sure that's also true for the broader @fhi-aims.bsky.social .

GPU - James Green just led an overhaul of our build tutorial fhi-aims-club.gitlab.io/tutorials/cm... - I'm sure he'll be delighted, too.

😊 Ok, so longer than 22 minutes? (Francium half life - or did I miss one in my search?)

Also, would be very interesting to get the other ones to converge. These are obviously a bit tough (multireference) but interesting nevertheless ...

Very impressive work by @labcosmo.bsky.social , @mahrossi.bsky.social and many others. And truly happy to see this:

"All calculations were performed with FHI-aims
(version 250806), an all-electron, numeric atom-centered
orbital (NAO) electronic-structure code"

Thank you!

Not so easy to ignore the first part either ...

Deeply, deeply sorry to see this.

I am shocked and incredibly sorry to hear that. I had no idea. I will be thinking about this quietly for a while. What an incredible, sudden, deep loss. So sorry!

(those dimers will grow up to become real materials real soon)

... but also that the Kohn-Sham DFT step (single reference auxiliary wave function) and its implications should not be forgotten when using standard, approximate DFT functionals. "Strong correlation" and the problems of DFT with it becomes much clearer if one just remembers that single reference.

Having just started the first in-class computational exercise for the 23 students in my "Computational Materials Science" class, I hope they still think so, too. Binding energy curves of 23 different dimers with different (simple) DFT functionals. ... shows if/how far binding energy curves work, ...

I thought "computational materials science" was the most exciting field ever ... ?

#chemsky #compchemsky

... see also the other posts by @diracprogram.bsky.social ...

Thank you!!

Hydrothermal Synthesis and Electronic and Optical Characterization of Ag2(NH4)AsS4 Multinary chalcogenide semiconductors have the potential for use in various optoelectronic and energy-conversion applications. Understanding how to controllably synthesize these semiconductors is paramount to successful device integration. In this report, we analyze the hydrothermal synthesis technique used to make the quaternary sulfide Ag2(NH4)AsS4, focusing on how solvent volume, synthesis time, sulfur background pressure, and initial cation stoichiometry impact the synthesis result. Achieving a reliable synthesis procedure, we characterize the thermal and air stability, calculate the electronic band structure, and measure the optical absorption of Ag2(NH4)AsS4. The sulfide is found to be relatively stable to air exposure at room temperature but is susceptible to thermal decomposition at temperatures below the typical synthesis point (∼220 °C). Ab initio molecular dynamics simulations show that the NH4+ cation can rotate freely within the structure, and single crystal X-ray analysis of Ag2(NH4)AsS4 shows no structural transitions over the temperature range 135–298 K. Hybrid density functional theory calculations indicate that Ag2(NH4)AsS4 is an indirect band gap semiconductor with dispersive band edges, while optical spectroscopy reveals a 2.05(5) eV band gap. The thorough synthesis and materials characterization studies pursued here lay a foundation for film processing of Ag2(NH4)AsS4 and the exploratory synthesis of related quaternary chalcogenides.

And here is the second paper, this time Garrett Wessler on an ammonia containing multinary chalcogenide semiconductor, with help from Tianlin Wang and Gabe Graf (theory) and Colin Brown (experiment) in David Mitzi's group:
doi.org/10.1021/acs....

So thank you!! also to @fhi-aims.bsky.social ... these simulations run on reasonable hardware now, all-electron and accurate. The work of a very large group of people made this happen.

Local Symmetry Breaking in 3D Hybrid Perovskites with 3-Hydroxyazetidinium Two-dimensional (2D) hybrid perovskite semiconductors with nonprimary ammonium cations (NPACs) have recently attracted interest for spin-optoelectronics owing to the symmetry-breaking distortions in their crystal structures. However, implementing this design strategy in three-dimensional (3D) analogs remains largely unexplored, primarily due to stricter restrictions on cation size. Here, we introduce a family of 3D hybrid perovskites (3DHPs), ASnX3, where A = 3-hydroxyazetidinium (AzOH; +NH2(CH2)2CHOH) and X = Cl, Br, and I. The choice of a bulky NPAC, coupled with the incorporation of a polar group (−OH), targets broken symmetry within the 3D frameworks. While single-crystal X-ray diffraction analysis reveals spatially averaged centrosymmetric cubic (i.e., Pm-3m space group) unit cells, with the largest lattice parameters among existing ASnX3 analogs, first-principles molecular dynamics and electronic structure calculations indicate that the relatively fixed dipoles of AzOH within the SnX6-derived framework introduce local inversion asymmetry and spin polarization. By incorporating a polar cation with limited mobility into the 3D perovskite framework, (AzOH)SnX3 unlocks potential for spin-optoelectronics, photovoltaics, ferroelectrics, and nonlinear optics.

Here is Rayan Chakraborty's masterpiece
doi.org/10.1021/jacs...
showing some new 3D halide perovskites. That's very rare! Again, thanks to Department of Energy, NSF and Duke Climate Initiative. Oh, and a modest 3672 atom DFT simulation probing the local order (along with many other simulations)!

Two new papers including our group appeared online yesterday, both theory+experiment and both with the truly remarkable group of David Mitzi. All of it is research of new semiconductors, enabled by Department of Energy, National Science Foundation, and Duke Climate Initiative. Will post the next.

Take a look and spread the word - great opportunity if you're looking for a Ph.D. in chemistry / #compchem / computational materials science.

mid-career median earnings of $100,000 or more

"mid-career median earnings of $100,000 or more"
www.cnbc.com/2026/02/21/h...

The 18 highest-paying college majors 5 years after graduation

"The 18 highest-paying college majors 5 years after graduation"
www.cnbc.com/2026/02/21/h...

The short term consequences are pretty clear. Retain heat for a longer period of time, increase average temperature. This is pretty simple. And we now have the technology to stop this trend.

For the beginning of the week - this is a startling graph. My guess is that anyone who reads this post already knows. Still.

Selfie at BPS 2026

I’m at the BPS2026 meeting @biophysicalsoc.bsky.social in San Francisco. Find me to talk science or if you want some @mdanalysis.bsky.social stickers.

Avogadro Stories (for 2.0 Release) As we finish up the 2.0 (final!) release, I’d like to feature some stories (and citations) about how Avogadro has shaped research and teaching. So if Avogadro has helped your research, please let me ...

Has @avogadro.cc helped your research? Teaching?

As we prepare Avogadro 2.0 for release this spring, I'm hoping to feature some stories (and citations).

#compchem #opensource #openscience ⚗️

Let me know:
discuss.avogadro.cc/t/avogadro-s...

Plötzlich Zeit.

Yes, seconded!

Exploration, Prediction, and Experimental Verification of Structure and Optoelectronic Properties in I2-Eu-IV-X4 (I = Li, Cu, Ag; IV = Si, Ge, Sn; X = S, Se) Chalcogenide Semiconductors Recently, there has been extensive research into photovoltaic, thermoelectric, and nonlinear optical applications of chalcogenide semiconductors within the large set of defect-resistant I2-II-IV-X4 (I...

Hm, we have only one where the computation was arguably first, Cu2EuSnSe4, doi.org/10.1021/acs.... . The Materials Project claims a few others I think ... ?

So it was a quiet week then? How much better does it get? ;)

Actually, for those who use @fhi-aims.bsky.social , a minor release (typically defined as one-line type bug fixes) "250822_1" was just released - see fhi-aims.org for details and THANK YOU to everyone who worked on this!