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marcel ⊙

@marceldotsci.bsky.social
82 followers 63 following 56 posts

Trying to build better machine-learning surrogate models for DFT. Postdoc @ COSMO Lab (EPFL) 👨🏻‍🚀. marcel.science

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marcel ⊙ @marceldotsci.bsky.social · 02/10/2026
happy to have played a (very small) part in this paper: arxiv.org/abs/2610.00794, studying some of the pitfalls and difficulties of training long-range models to represent actual electrostatics. go have a read!
arxiv.org
Long-Range Machine Learning Interatomic Potentials for Defect Energetics in SrTiO$_3$
Machine learning interatomic potentials (MLIPs) have advanced rapidly in recent years, yet the majority of models remain semilocal in nature and neglect long-range electrostatic interactions. A growin...
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marcel ⊙ @marceldotsci.bsky.social · 28/09/2026
let's gooooo
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marcel ⊙ @marceldotsci.bsky.social · 18/09/2026
Preprint: arxiv.org/abs/2609.20510 Overview website: marcel.science/tasd4mlip/ Code should eventually land in github.com/lab-cosmo/pe...
arxiv.org
Truncated automatic sparse differentiation for machine learning interatomic potentials
Machine learning interatomic potentials (MLIPs) learn the mapping from atomic positions to potential energy. The forces, the negative gradient of this energy, drive molecular dynamics and are readily ...
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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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marcel ⊙ @marceldotsci.bsky.social · 04/08/2026
is jax 0.11.0 producing rather weird behaviour for anyone else? we're seeing slowdowns and nans under jit.
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marcel ⊙ @marceldotsci.bsky.social · 07/07/2026
@anthropic.com
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marcel ⊙ @marceldotsci.bsky.social · 07/07/2026
asked fable to "orient yourself in this project so we can continue discussing what comes next"
Meme with Arnold and the text  Made 1 scratchpad edit +25, committed d7bcfd9, pushed to megabatch, searched for 1 pattern, read 4 files, listed 1 directory, ran 13 shell commands
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marcel ⊙ @marceldotsci.bsky.social · 23/04/2026
little footgun in jax.nn.dot_product_attention for the double precision enjoyers out there: github.com/jax-ml/jax/b...
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marcel ⊙ @marceldotsci.bsky.social · 20/03/2026
🏃🏻‍♂️ largely because the name was too tempting, partially to support the upcoming LOREM release & make CI less annoying, my hackable personal jax training infra is now on PyPI pypi.org/project/mara... — featuring a beautiful logo drawn by a dear friend
running greek guy
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marcel ⊙ @marceldotsci.bsky.social · 29/01/2026
you need to think with AI, the future is text
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marcel ⊙ @marceldotsci.bsky.social · 29/01/2026
good reaction: blog.joss.theoj.org/2026/01/prep...
blog.joss.theoj.org
Preparing JOSS for a generative AI future: From code to human creativity and design | Journal of Open Source Software Blog
Blog for the Journal of Open Source Software • <a href='https://joss.theoj.org'>https://joss.theoj.org</a>
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marcel ⊙ @marceldotsci.bsky.social · 29/01/2026
www.robinsloan.com/winter-garde...
robinsloan.com
AGI is here (and I feel fine)
I propose to begin this year with an acknowledgment that is strategic but/and also sincere.
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marcel ⊙ @marceldotsci.bsky.social · 27/01/2026
my long bet to not bother to learn vim commands has finally paid off #sloperator
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marcel ⊙ @marceldotsci.bsky.social · 04/12/2025
thank you adrian, that‘s a very poignant quote 😔
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marcel ⊙ @marceldotsci.bsky.social · 03/12/2025
congrats to you two! well deserved!
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marcel ⊙ @marceldotsci.bsky.social · 30/11/2025
i may be biased but this is a very nice example of a universal MLIP paper
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marcel ⊙ @marceldotsci.bsky.social · 30/11/2025
those are the shiniest potatoes i’ve ever seen
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marcel ⊙ @marceldotsci.bsky.social · 28/11/2025
reality is proving @adrianhill.de more right by the minute -- now all reviews have been reverted to their pre-discussion state. someone remind me why i spent a week+ preparing rebuttals and reading author comments?
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marcel ⊙ @marceldotsci.bsky.social · 28/11/2025
ICLR2026 is truly the gift that keeps on giving
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Adrian Hill @adrianhill.de · 28/11/2025
When it comes to drama, ICLR 2026 is truly the gift that keeps on giving.
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Michele Ceriotti @micheleceriotti.bsky.social · 26/11/2025
made by a friend of a colleague. iykyk
a meme with scilla and cariddi and ulysses ship trying to sail through, making fun of the peer review process at ICLR
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marcel ⊙ @marceldotsci.bsky.social · 12/11/2025
seems like i was the only ICLR reviewer that bothered to declare LLM usage
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Adrian Hill @adrianhill.de · 19/09/2025
This also shows that @typst.app is already a viable alternative to LaTeX for top conferences in ML!
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Adrian Hill @adrianhill.de · 19/09/2025
Our paper on XAI + Automatic Differentiation got accepted at #NeurIPS2025. Can't wait to share the camera-ready soon! 🥳
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COSMO Lab @labcosmo.bsky.social · 08/08/2025
If you are excited about 30x longer time steps in molecular dynamics using FlashMD, but are worried about it not being symplectic, Filippo has something new cooking that should make you even more excited. Head to the #arxiv for a preview arxiv.org/html/2508.01...
Orbits for a periodic 3-body system, showing the stability of a ML long-time integrator
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marcel ⊙ @marceldotsci.bsky.social · 08/08/2025
for the jax kids, i just made my personal training infra repo public: github.com/sirmarcel/ma... -- happy for some feedback/ideas/takes!
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Jan Hermann @hrmnn.net · 03/08/2025
I benefited massively from www.ipam.ucla.edu/programs/lon.... I got into ML for science through that program. Now IPAM may be gone mathstodon.xyz/@tao/1149568...
mathstodon.xyz
Terence Tao (@tao@mathstodon.xyz)
The current administration in the US has, through various funding agencies such as the NSF and NIH, has recently suspended virtually all federal grants to my home university, UCLA (including my own p...
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Volker Blum @aimsduke.bsky.social · 06/08/2025
This, if true, is incredible. A long program in 2011 at IPAM that I attended practically wrote the book on machine learning in materials science, which is now AI. Not funding IPAM would be deeply destructive to US leadership in critical future technologies! Hard to fathom.
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marcel ⊙ @marceldotsci.bsky.social · 05/08/2025
Absolute insanity. IPAM is where I first heard about equivariant NNs! What a loss.
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marcel ⊙ @marceldotsci.bsky.social · 05/08/2025
this is work at @labcosmo.bsky.social with Egor, Tulga, Philip & @micheleceriotti.bsky.social!
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marcel ⊙ @marceldotsci.bsky.social · 05/08/2025
... overall, it seems that we need more challenging benchmarks. or maybe LR behaviour is simply "not that complicated". we will see. the manuscript is here: arxiv.org/abs/2507.19382 & code & data are coming out soon-ish, once i run a few more ablations. looking forward to feedback!
arxiv.org
Learning Long-Range Representations with Equivariant Messages
Machine learning interatomic potentials trained on first-principles reference data are quickly becoming indispensable for computational physics, biology, and chemistry. Equivariant message-passing neu...
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marcel ⊙ @marceldotsci.bsky.social · 05/08/2025
... and show that it works pretty well on a few long-range benchmark datasets. but we also find that many benchmark tasks are easily solved even by short-range message passing, so we run a few more targeted experiments to see where it fails & confirm that LOREM works for these ...
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marcel ⊙ @marceldotsci.bsky.social · 05/08/2025
✨preprint alert: "learning long-range representations w/ equivariant messages" in which we get into the fray of long-range MLIPs and propose to use equivariant charges w/ classical electrostatics as long-range MP mechanism. we design LOREM, an equivariant MLIP, around this ...
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marcel ⊙ @marceldotsci.bsky.social · 20/06/2025
very proud of filippo
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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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COSMO Lab @labcosmo.bsky.social · 20/06/2025
So kudos to 🧑‍🚀 Filippo and @marceldotsci.bsky.social bsky.app/profile/labc..., thanks to funders @erc.europa.eu @snf-fns.ch @cscsch.bsky.social and @nccr-marvel.bsky.social, and go to Filippo's talk if you are at #icml25, to see this nice mix of #compchem and #machinelearning!
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marcel ⊙ @marceldotsci.bsky.social · 16/06/2025
obvious in hindsight but news to me: accessing np.load-ed arrays by index is orders of magnitude slower than forcing them to RAM. notes.marcel.science/2025/numpy-l...
notes.marcel.science
numpy.load access performance – marcel's notes
marcel's science notes
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marcel ⊙ @marceldotsci.bsky.social · 16/06/2025
ok then thanks
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marcel ⊙ @marceldotsci.bsky.social · 04/06/2025
very annoying when papers don‘t include raw data for plots
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marcel ⊙ @marceldotsci.bsky.social · 27/05/2025
⚡️
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marcel ⊙ @marceldotsci.bsky.social · 08/04/2025
🍾
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marcel ⊙ @marceldotsci.bsky.social · 20/03/2025
Hm... yeah, it's okay, but my impression from talking to practitioners is that its speed is not particularly impressive. (Because of the tensor products.) That's why it's a bit concerning that the LLM wrote it into the table... 😇 "Hot take" indeed!
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marcel ⊙ @marceldotsci.bsky.social · 20/03/2025
MACE is not generally considered fast, right? 🧐
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marcel ⊙ @marceldotsci.bsky.social · 19/03/2025
cosmo has joined the universal FF club!
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marcel ⊙ @marceldotsci.bsky.social · 16/02/2025
watch out cancer, mihail is coming for you 🔥
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Adrian Hill @adrianhill.de · 13/02/2025
Completed my post preprint project: a split keyboard to help with my wrist pain (pictured with the pain-relieving gel it is trying to replace).
Two halves of a 3D printed ergonomic split keyboard surrounding pain relief gel.
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marcel ⊙ @marceldotsci.bsky.social · 13/02/2025
sick!
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marcel ⊙ @marceldotsci.bsky.social · 11/02/2025
anyone at the lausanne applied ML days?
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COSMO Lab @labcosmo.bsky.social · 05/02/2025
@marceldotsci.bsky.social getting into very dangerous territory.
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marcel ⊙ @marceldotsci.bsky.social · 31/01/2025
same down to last minute upload 🤝
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