FACCTs

Assessing Isomerization Potential of Plant Protection Products on Leaf Surfaces by Dislodgeable Foliar Residue Studies and a Simple Quantum Chemical Calculation Protocol A small-scale dislodgeable foliar residue (DFR) study setup in the greenhouse was applied and validated to determine the parameters influencing the isomerization of active substances on the leaf surfa...

#WEASEL helps our industry partners at Bayer solve real world challenges using quantum chemistry.

Check out their paper investigating the isomerization potential of plant protection products on leaf surfaces.

pubs.acs.org/doi/full/10....

#QuantumChem #Agrochemistry #PlantProtection #Workflows

FACCTs at the Analytica 2026

On March 24, #analytica 2026 kicks off in Munich — and we’re excited to be part of it.

Experience #WEASEL, #ORCA, and more live and discover how our solutions elevate your processes to a new level of efficiency.

We look forward to seeing you there

#FACCTs #QuantumChem #Workflows #AnalyticalChem

With our latest #WEASEL release, it is time to introduce another workflow: the fully automated calculation of rotational barriers for arbitrary molecules, enabling the reliable identification and classification of #atropisomers.

www.faccts.de/weasel/

#FACCTs #Workflows #QuantumChem #CompChem #CADD

Two teams, one quest: democratizing quantum chemistry. We’re very happy to support the fantastic team at @thematterlab.bsky.social and to see this great achievement. Many thanks as well for trusting the ORCA quantum chemistry package!

#ORCAqc #QuantumChem #AgenticAI #ElAgente

QUICHE Project - FACCTs The QUICHE project is a UK–Germany Collaboration Bringing Chemistry Software into the Quantum Computing Era

We are proud to be part of the Quantum Integrated Chemistry #QUICHE project, funded by ZIM and Innovate UK. Teaming up with Quantum Motion and Riverlane we strive to enable quantum-ready calculations within #ORCA

Learn more: www.faccts.de/quiche-proje...

#QuantumChem #QuantumComputing #Workflows

Redoxpotentials with ORCA and OPI

Check out the new Jupyter notebook on the calculation of redox potentials with #ORCA and #OPI by #FACCTs Computational Scientist Hagen Neugebauer:

www.faccts.de/docs/opi/nig...

OPI Docs: www.faccts.de/docs/opi/docs/
OPI GitHub: github.com/faccts/opi

#ORCAqc #ORCAPI #CompChem #Python #ChemSky

The photohydrolysis of furans The defossilization of the chemical industry is accelerated by the shift from petroleum- to biomass-based feedstocks. At the center stage are bioderived furans, from which valuable platform chemicals ...

Check out the recent work on the photohydrolysis of furans by List et al., with contributions from Benjamin Helmich-Paris. For a quick start on GOAT, DLPNO-CCSD(T), and more also check our ORCA tutorials www.faccts.de/docs/orca/tu....

doi.org/10.1126/scie...

#MPIKOFO #FACCTs #CompChem #ORCAqc

FACCTs at the JCF FJS 2026

Young, curious scientists are our future. That’s why we’re especially delighted to sponsor this year’s #JCF Frühjahrssymposium in our hometown of Cologne. We’re looking forward to meeting many of you there!

symposium.jcf.io

#FACCTs #FJS2026 #JungesChemieForum #GDCh #ORCAqc #OPI #ChemSky

FACCTs at the CCSC 2026

We’re excited to sponsor this year’s #CCSC2026.

Meet us in Munich to learn more about the latest ORCA features and our ORCA Python Interface #OPI. We’re looking forward to seeing you there!

CCSC: ccsc2026.github.io
ORCA: www.faccts.de/orca/
OPI: github.com/faccts/opi

#FACCTs #ORCAqc #CompChem #ML

Great to see applications of #ORCA's External Optimizer feature! Let us know which methods you'd like to use with it in the future.

Check out our tutorials on ExtOpt: www.faccts.de/docs/orca/6....

#ORCAqc #CompChem #ExtOpt

100000 registered ORCA users!

What an incredible Christmas gift!

The #ORCA community has reached a major milestone: 100,000 registered users.
Thank you all for your trust and for being such an important part of ORCA’s journey. Your support is what makes this success possible.

#ORCAqc #FACCTs #MPIKOFO #CompChem #ChemSky

Happy Holidays!

We at FACCTs wish you all a wonderful and peaceful holiday season and a great start to the new year!

#FACCTs #ORCAqc #WEASEL #Holidays

Ligand Field Tuning of Photoreactivity: Contrasting Low‐Spin and High‐Spin Fe(III)‐Azido Complexes Why do near-identical Fe(III)-azido complexes exhibit different photoreactivity profiles? Linking spin states and key normal modes to wavelength-dependent photoreductive and photooxidative reaction p...

#CASSCF and (TD-)DFT are well-established components of #ORCA's method portfolio. Check out the new paper by Krewald et al., who use both for tuning the photoreactivity of Fe(III)-azido complexes.

doi.org/10.1002/cptc...

CASSCF in ORCA: www.faccts.de/docs/orca/6....

#ORCAqc #CompChem #QuantumChem

Use Fukui functions to estimate molecular reactivity and pinpoint reactive sites. With #WEASEL, you can visualize them and get all associated indices easily using just one command!

Learn more about WEASEL www.faccts.de/weasel

#FACCTs #CompChem #QuantumChem #Fukui #Reactivity #WorkflowAutomation

We are proud to announce that ORCA 6.1.1 has been released and is available here:

orcaforum.kofo.mpg.de/app.php/dlex...

This is strictly a bugfix release that takes care of the problems that have been reported since the release of ORCA 6.1. The manual has also been updated.

GitHub - faccts/opi: ORCA Python Interface ORCA Python Interface. Contribute to faccts/opi development by creating an account on GitHub.

Nice work, have you also checked out our ORCA-Python-Interface OPI? May be interesting for your projects github.com/faccts/opi

Keep on having fun with ORCA!

IM-CCS with WEASEL

Efficiency, robustness, adaptability. Three aspects that characterize our #WEASEL workflows!

One of WEASELs workflows is IM-CCS prediction which reliably predicts #IMCCS with a MARD of 1.7% (2.9 Å) for a set of 48 molecules.

Check out WEASEL at www.faccts.de/weasel.

#FACCTs #ChemSky #CompChem

The video is up in YouTube! CASSCF with ORCA, merging metal and ligand fragment wavefunctions to retrieve all metal 3d orbitals.
#compchem #chemsyk #CASSCF #Corrole #ORCA

youtu.be/LAm9jEFDjKM

We are hiring a Front-End Engineer!

Help us realizing a web application for molecular structure and quantum chemical dataset exploration through advanced 2D and 3D visualizations. The full job description is available at:

www.faccts.de/careers/#ope...

#OpenPosition #FrontEnd #CompChem #ChemSky

Academia meets industry
Yesterday, we welcomed around 100 scientists and company representatives to celebrate the World Science Day for Peace and Development at our annual networking event. This year’s focus: young researchers and career opportunities in industry.
#SolvationScience #WorldScienceDay

Quantum chemistry and large systems – a personal perspective This perspective offers a personal reflection on the evolution, current status, and open challenges of quantum chemistry in the context of large molecular systems. Beginning with Dirac’s famous 1929 p...

Sometimes, one is given the opportunity to freely write about one's own opinions and perspectives. In this perspective, I have reflected on the history of our field, its accomplished and unaccomplished missions as well as some speculations about the future.

doi.org/10.1515/pac-...

New paper with my colleagues at #UFRRJ and #UFRGS. In this work #ORCA nailed to show in extreme detail the formation process of a zinc complex AND the charge transfer. Yes, we have AIMD, we have DLPNO-CCSD(T) and a little bit of TD-DFT.

#CompChem #ChemSky

doi.org/10.1016/j.dy...

Electronic Structure and Hypercorrole Features of Deprotonated Free-Base and Reduced Copper Corroles We report the synthesis, crystal structure, and spectroscopic and computational electronic-structural characterization of two copper corroles, [Cu(5,15-bis(4-methylcarboxyphenyl)-10-(2-methylcarboxyphenyl)corrole)] (1Cu) and [Cu(5,15-bis(4-nitrophenyl)-10-(2-methylcarboxyphenyl)corrole)] (2Cu), as well as spectroscopic and computational studies on the corrole ligands (H3L1 and H3L2) in their neutral and anionic forms. We have found that the anionic corroles containing the 4-nitrophenyl substituents in positions 5 and 15 of the corrole ring show hypercorrole behavior, where the Q-bands are considerably more intense and red-shifted compared to those in the 4-methylcarboxyphenyl-substituted corroles. Electronic structure calculations using wave function methods (CASSCF/NEVPT2) reveal that the intense Q-bands, which extend slightly into the NIR region, are charge-transfer bands from the anionic corrole core to the strongly electron-withdrawing 4-nitrophenyl substituents. We further show that 2Cu can be reduced indirectly in the presence of excess F– or OH–, and the Q-band shifts toward the red in the polar environment containing the corresponding salts. Our study provides examples of easy-to-prepare anionic corroles, metalated and unmetalated, that show hypercorrole behavior and NIR absorption, and thus could find use in hyperthermal processes.

Finally our paper on copper corroles is out in Inorganic Chemistry @pubs.acs.org!

#chemsky #realtimechem #science #comp_chem
1/n

Electronic Structure and Hypercorrole Features of Deprotonated Free-Base and Reduced Copper Corroles | Inorganic Chemistry pubs.acs.org/doi/10.1021/...

FACCTs at the RESOLV World Science Day 2025

We will be presenting at the World Science Day in Bochum, organized by RESOLV! We look forward to seeing many of you at this fantastic science and industry networking event.

www.solvation.de/news/resolv-...

#FACCTs #RESOLV #WorldScienceDay25 #ScienceMeetsIndustry #Innovation

WEASEL YouTube video by FACCTs

Most people know us for our contributions to ORCA — but have you heard of WEASEL?

WEASEL is our smart workflow driver that delivers efficient workflows for complex quantum chemical processes.

Learn more about WEASEL at www.faccts.de/weasel

youtu.be/stYgkMZwi5s

#WEASEL #FACCTs #CompChem #ChemSky

Notizen aus der Forschung Click on the article title to read more.

GDCh wrote a section about our work! Solvent and system specific radii for CPCM with consistent analytic gradients.

Check out the GDCh article (doi.org/10.1002/nadc...) or our work (doi.org/10.1002/jcc....)!

#compchem #quantumchemistry

FACCTs at the SMASH 2025

Visit Anneke Dittmer, Bernardo de Souza, and Christoph Riplinger at the SMASH in beautiful Porto! Get the latest information about our quantum chemical NMR toolkit. We look forward to seeing you there!

#FACCTs #ORCAqc #SMASH2025 #CompChem #TheoChem #NMR

FACCTs at the STC 2025

We are visiting STC in Berlin! Come and join us at our poster presentation—we look forward to many exciting discussions with you! Also check out all the new ORCA features and the new ORCA Python interface, OPI!

#FACCTs #ORCAqc #STC2025 #CompChem #TheoChem

I have an open PhD position. The exact topic is negotiable and can range from implementing new quantum-chemical methods in @orca-qc-official.bsky.social to computational studies of open-shell molecules.
🔗 Details: www.langresearch.org/open-phd-fel...

Please share!

#PhDposition #CompChem

We've got a new release 1.101, which should particularly fix some bugs with Windows and Mac, and of course a variety of new features.

Highlights include support for constraints for geometry optimizations, tweaking bond lengths when changing elements, and more...

discuss.avogadro.cc/t/avogadro-1...