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Guillaume Fraux

@luthaf.bsky.social
92 followers 103 following 16 posts
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Reposted by Guillaume Fraux
marcel ⊙ @marceldotsci.bsky.social · 18/09/2026
✨ new work: "Truncated automatic sparse differentiation for MLIPs" with @adrianhill.de & @micheleceriotti.bsky.social has arrived on the arXiv. In a 🥥: we exploit that MLIP Hessians are sparse and decay with distance with a "truncated" variant of automatic sparse differentiation. See figure. 👇
Truncated automatic sparse differentiation (ASD). (a) Toy chain of 7 atoms, model reach K = 2 hops. The Hessian H is recovered from Hessian-vector products (HVPs) with the columns of a seed matrix S, giving the compressed product HS. Since H is sparse, star coloring needs 5 colors, hence 5 HVPs instead of 7. Each entry of H is read from one entry of HS (its hue), directly or via its symmetric partner; entries that are sums are never read (crossed). Truncating to one hop needs only 3 HVPs, but the neglected two-hop couplings (gray) now contaminate entries that are read (dots), causing errors. (b) MOF-177 with PET-XS: atoms within K = 5 hops of one Zn atom in the model's graph, with its cutoff sphere and one-hop edges; rest of the cell in gray. (c) Same atoms colored by the force-constant block norm ‖Φᵢⱼ‖ to the marked atom, decaying with distance. (d) Whole Hessian of MOF-177, one cell per atom pair, graph neighbors adjacent: hop count above the diagonal, ‖Φᵢⱼ‖ below, zeros white.
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Reposted by Guillaume Fraux
Matthias Kellner @matthiaskellner.bsky.social · 18/09/2026
We have released ShiftML4! ShiftML4 comes with built-in molecular corrections, elevating the chemical shielding predictions to hybrid-DFT level quality. Try it yourself on shiftml.org, or from the PyPi package.
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Reposted by Guillaume Fraux
Peter Spackman @crystalexplorer.net · 05/06/2026
I don’t have the budget for hundreds of GPUs or even a backend, so I had to make mine use your local resources 🤓 peterspackman.github.io/mlip.cpp/
peterspackman.github.io
mlip.js - ML Interatomic Potentials in the Browser
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 03/03/2026
Now, this is just a milestone on that path, but it's already something worth sharing, so thanks to arXiv you can read about it arxiv.org/html/2603.02..., and thanks to uPET github.com/lab-cosmo/up... and metatomic, you can try already a universal MLIP trained on it.
github.com
GitHub - lab-cosmo/upet: Universal interatomic potentials for advanced materials modeling
Universal interatomic potentials for advanced materials modeling - lab-cosmo/upet
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 03/03/2026
📢 We have been working on a new universal atomistic dataset that combines the principles of MAD with a meta-GGA level of theory, so we can all simulate water that does not freeze at 500K 🧊 , and have all our bases covered, with reference data for every isotope with a half-life above 24 hours ☢️
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 03/03/2026
So let us show you just how *universal* #PET-MAD-1.5 can be. This is a movie of a parallel tempering simulation, with replicas from 300K to 3000K, of what we call a "Mendeleev cluster" - one atom each of every element from 1 to 102.
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Reposted by Guillaume Fraux
Matthias Kellner @matthiaskellner.bsky.social · 17/02/2026
No Install. No Setup. Just Chemical Shift Predictions. At shiftml.materialscloud.io we host the latest ShiftML3 in the web and you can predict chemical shifts of organic crystals for free in the web!
shiftml.materialscloud.io
ShiftML-3 predictor
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 05/01/2026
📢 chemiscope.org 1.0.0rc1 just dropped on pypi! We are making (a few) breaking changes to the interfaces, fixing a ton of bugs and introducing some exciting features (you can finally load datasets with > 100k points!). We'd be grateful if you test, break and report 🐛 github.com/lab-cosmo/ch...
Zooming in on a large-scale dataset to showcase the new adaptive resolution features in chemiscope
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 28/11/2025
📢 PET-MAD is here! 📢 It has been for a while for those who read the #arXiv, but now you get it preciously 💸 typeset by @natcomms.nature.com Take home: unconstrained architecture + good train set choices give you fast, accurate and stable universal MLIP that just works™️ www.nature.com/articles/s41...
nature.com
PET-MAD as a lightweight universal interatomic potential for advanced materials modeling - Nature Communications
PET-MAD is a fast and lightweight universal machine-learning potential, trained on a small but diverse dataset, that delivers near-quantum accuracy in atomistic simulations for both organic and inorga...
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Reposted by Guillaume Fraux
Matthias Kellner @matthiaskellner.bsky.social · 25/08/2025
We're introducing ShiftML3, a new ShiftML model for chemical shielding predictions in organic solids. * ShiftML3 predicts full chemical shielding tensors * DFT accuracy for 1H, 13C, and 15N * ASE integration * GPU integration Code: github.com/lab-cosmo/Sh... Install from Pypi: pip install shiftml
github.com
GitHub - lab-cosmo/shiftml: A python package for the prediction of chemical shieldings of organic solids and beyond.
A python package for the prediction of chemical shieldings of organic solids and beyond. - lab-cosmo/shiftml
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Rocco Meli @rmeli.bsky.social · 25/08/2025
If you are using or you are considering using CP2K, check this out!
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COSMO Lab @labcosmo.bsky.social · 20/06/2025
Very proud to send Filippo Bigi to Vancouver to give an oral presentation at @icmlconf.bsky.social about our investigation of the use of "dark-side forces" in atomistic simulations. The final version is here openreview.net/forum?id=OEl... and it's worth a read even if you already read the #preprint
openreview.net
The dark side of the forces: assessing non-conservative force...
The use of machine learning to estimate the energy of a group of atoms, and the forces that drive them to more stable configurations, have revolutionized the fields of computational chemistry and...
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 17/06/2025
🎉 DFT-accurate, with built-in uncertainty quantification, providing chemical shielding anisotropy - ShiftML3.0 has it all! Building on a successful @nccr-marvel.bsky.social-funded collaboration with LRM🧲⚛️, it just landed on the arXiv arxiv.org/html/2506.13... and on pypi pypi.org/project/shif...
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COSMO Lab @labcosmo.bsky.social · 27/05/2025
We wouldn't be @labcosmo.bsky.social if we didn't want you to go break it, so head to atomistic-cookbook.org/examples/fla... for a crash-course 🧑‍🍳📖 recipe, but not before reading the warnings arxiv.org/html/2505.19.... Have fun! #compchem #machinelearning #md @nccr-marvel.bsky.social @erc.europa.eu
atomistic-cookbook.org
Long-stride trajectories with a universal FlashMD model - The Atomistic CookbookContentsMenuExpandLight modeDark modeAuto light/dark, in light modeAuto light/dark, in dark mode
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 27/05/2025
If you do, the rewards can be very impressive: you can run solvated alanine dipeptide and observe superionic behavior in LiPS with 16fs time step, and watch the Al(110) surface pre-melt in strides of 64fs. And all with the same universal model, no fine-tuning needed!
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 27/05/2025
Much as for direct force prediction [ arxiv.org/html/2412.11... ] you better know what you are doing: you've no guarantee of energy conservation, or of equipartition, so you should know your thermostats VERY well. Caveat emptor.
Darth Vader dressed as Santa presents a non-conservative forcefield
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 27/05/2025
Filippo's idea was to use the heavy-duty PET-MAD model [ arxiv.org/html/2503.14... ] to generate a bunch of trajectories of wildly different compounds and use a PET-like architecture to learn (q',p') from (q,p), and and to think A LOT about the many things that could possibly go wrong.
arxiv.org
PET-MAD, a universal interatomic potential for advanced materials modeling
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 27/05/2025
There are reports as early as 2021 [cf. arxiv.org/abs/2111.15176 ] of using neural nets to predict a MD trajectory in large strides, but these were usually limited to a single system in a given thermodynamic state point. Nice, but not life-changing.
arxiv.org
Learning Large-Time-Step Molecular Dynamics with Graph Neural Networks
Molecular dynamics (MD) simulation predicts the trajectory of atoms by solving Newton's equation of motion with a numeric integrator. Due to physical constraints, the time step of the integrator need ...
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 27/05/2025
📢 Running molecular dynamics with time steps up to 64fs for any atomistic system, from Al(110) to Ala2? Thanks to 🧑‍🚀 Filippo Bigi and Sanggyu Chong, with some help from Agustinus Kristiadis, this is not as crazy as it sounds. Let us briefly introduce FlashMD⚡ arxiv.org/html/2505.19...
Scheme of the GNN architecture of the FlashMD method.
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 09/05/2025
If you don't want to read, but want to cook, guess what? The 🧑‍🍳📖 #atomistic-cookbook has you covered. Head to atomistic-cookbook.org/examples/lea... to see how to use this, as simple as `mtt train mymodel.yaml`.
atomistic-cookbook.org
Equivariant model for tensorial properties based on scalar features - The Atomistic CookbookContentsMenuExpandLight modeDark modeAuto light/dark, in light modeAuto light/dark, in dark mode
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 09/05/2025
If you don't have time for the 20-pages appendix, the TL;DR is that approximating tensors is harder than the vector case, but can be made as simple as possible using angular momentum theory. The practical implementation we propose is not as rigorous, but works well and is very fast in practice.
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COSMO Lab @labcosmo.bsky.social · 09/05/2025
First #preprint from recent 🧑‍🚀 Michelangelo Domina (+ @ppegolo.bsky.social and Filippo) provides theoretical foundations and practical architectures to build scalar-function-based approximations of tensors, in the spirit of the "scalars are universals" paper #compchem arxiv.org/html/2505.05...
Schematic representation of the lambda-MCoV architecture for predicting tensorial quantities using scalar approximators
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COSMO Lab @labcosmo.bsky.social · 07/05/2025
You can use these safely in MD, by multiple time stepping (a '90s classic: doi.org/10.1063/1.46...) so you get reliable conservative trajectories, for any material, twice as fast! Let us know if it works for you, and even more importantly, if it doesn't! 👉 atomistic-cookbook.org/examples/pet...
doi.org
Reversible multiple time scale molecular dynamics
The Trotter factorization of the Liouville propagator is used to generate new reversible molecular dynamics integrators. This strategy is applied to derive reve
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 07/05/2025
The PET-MAD universal forcefield mingled with the dark side, and got twice as fast 🚀. Read on, or head to the 🧑‍🍳📖 atomistic-cookbook.org/examples/pet..., if you are curious of what this is all about. #atomistic-cookbook #compchem #machinelearning #mlip🧵
Plot of the potential and total energy trends along a MD trajectory, showing drift for non-conservative forces, and how that is fixed using multiple time stepping.
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 08/04/2025
📢 For those who missed the #preprint, torch-pme is now published in @aip.bsky.social #JChemPhys. #compchem classics like Ewald and P3M meet #machine learning. Read all about it here pubs.aip.org/aip/jcp/arti...
pubs.aip.org
Fast and flexible long-range models for atomistic machine learning
Most atomistic machine learning (ML) models rely on a locality ansatz and decompose the energy into a sum of short-ranged, atom-centered contributions. This lea
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Reposted by Guillaume Fraux
COSMO Lab @labcosmo.bsky.social · 19/03/2025
You can read all about it here, arxiv.org/abs/2503.14118, see it in action as a #cookbook recipe 🧑‍🍳 atomistic-cookbook.org/examples/pet... or rush to install it following the instructions here github.com/lab-cosmo/pe...
Header for the atomistic-cookbook.org recipe for the PET-MAD universal potential
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COSMO Lab @labcosmo.bsky.social · 19/03/2025
📢 PET-MAD has just landed! 📢 What if I told you that you can match & improve the accuracy of other "universal" #machinelearning potentials training on fewer than 100k atomic structures? And be *faster* with an unconstrained architecture that is conservative with tiny symmetry breaking? Sounds like 🧑‍🚀
Polar plot showing the errors of several machine-learning potential of different test sets. Smaller is better here!Plots showing the evaluation time per atom for several machine-learning potentials as a function of the number of atoms in a simulation. Smaller is better
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COSMO Lab @labcosmo.bsky.social · 13/03/2025
Should be super-easy to adapt to whatever tensor you're trying to learn (and to extend to more sophisticated models than symmetry-adapted regression). Let us know what you cook with it 😋!
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COSMO Lab @labcosmo.bsky.social · 13/03/2025
In particular, this recipe relies on metatensor.github.io/featomic to compute the features, and the docs.metatensor.org/latest/torch... backend of #metatensor to export a self-contained ASE-compatible calculator. Easy to use, fast, and accurate.
metatensor.github.io
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COSMO Lab @labcosmo.bsky.social · 13/03/2025
🧑‍🍳 A new #cookbook recipe to train, export and use a simple but effective linear model for tensorial properties - specifically molecular polarizabilities atomistic-cookbook.org/examples/pol... Thanks @ppegolo.bsky.social for the recipe, and the whole 🧑‍🚀 team for the underlying infrastructure.
Polarizability of a small molecule, represented as an ellipsoid
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COSMO Lab @labcosmo.bsky.social · 28/02/2025
Happy to share a new #cookbook recipe that shocases several new software developments in the lab, using the good ole' QTIP4P/f water model as an example. atomistic-cookbook.org/examples/wat.... TL;DR - you can now build torch-based interatomic potentials, export them and use them wherever you like!
Header of the webpage showing the title ("Atomistic Water model for MD") and the authors (Philip Loche, Marcel Langer, Michele Ceriotti)
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Daniel Probst @skepteis.bsky.social · 27/02/2025
No, Overleaf, I don't want to use "AI" No, Outlook, I don't want to use "AI" No, Slack, I don't want to use "AI" No, DuckDuckGo, I don't want to use "AI" No, Samsung, I don't want to use "AI" No, my *fucking oven*, I don't want to use "AI"
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COSMO Lab @labcosmo.bsky.social · 05/02/2025
@marceldotsci.bsky.social getting into very dangerous territory.
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COSMO Lab @labcosmo.bsky.social · 28/01/2025
Interesting to note, packaging was by far harder than the actual implementation. Kudos to 🧑‍🚀 Filippo, @luthaf.bsky.social, and @cscsch.bsky.social Nick Browning for the perseverance!
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Patrick Walton @pcwalton.turbofishstudios.com · 29/01/2025
Maybe the biggest problem with LLMs as expert systems is that they can't say how confident they are. I'd be a lot more OK with LLMs sometimes giving incorrect answers if they didn't deliver those wrong answers as though they were certain.
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COSMO Lab @labcosmo.bsky.social · 28/01/2025
Very happy to announce that github.com/lab-cosmo/sp... has reached the 1.0 release milestone. Most notably, you can now `pip install sphericart[torch,jax]` and get it installed without compilation, complete with CUDA support where available. Spherical (& solid) harmonics made fast and easy!
An isosurface of a solid harmonic, incluing a visualization of its gradient.
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Guillaume Fraux @luthaf.bsky.social · 08/01/2025
Happy new year everyone! After more than three years of work, and splitting out a whole separate package, I am extremely happy to announce the first full public release of featomic, a package to compute representations for atomistic machine learning! github.com/metatensor/f... 1/n
github.com
GitHub - metatensor/featomic: Computing representations for atomistic machine learning
Computing representations for atomistic machine learning - metatensor/featomic
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COSMO Lab @labcosmo.bsky.social · 03/12/2024
Hello! I'm posting this both here and on the X-rated site, let's see where it gets more re-posts 😇. We are looking for a research software engineer to help us develop (even) better code for #compchem #atomicscale #machinelearning. Check out the specs and apply! www.epfl.ch/labs/cosmo/i...
epfl.ch
Jobs
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Guillaume Fraux @luthaf.bsky.social · 03/12/2024
I'm getting into the habit of announcing new code releases! So today's release is version 0.3.0 of vesin (luthaf.fr/vesin/), a small library to compute neighbor/pair lists for atomistic systems! This releases adds an option to sort the pairs and better integration with metatensor atomistic models.
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