SaddleFlow
Pick a structure in the Structure menu: an example, or upload your own periodic structure (a minimum: any file format ASE reads, e.g. CIF, POSCAR, extended XYZ). Choose the atoms that should react, then Generate: SaddleFlow FM2 adds noise to those atoms and flows them to a saddle point (a transition state) in 20 steps (4 passes of 5). Refine that guess with Sella + UMA, then generate the MEP (minimum energy path) to its two minima; the Show buttons replay each trajectory. Drag to rotate, right-drag to move, scroll to zoom, hover for atom numbers. Colours are the elements (Jmol), sizes as in the ASE GUI; chosen atoms have a magenta ring; atoms marked with a cross are fixed; the grey box is the periodic cell (a, b, c arrows).
An example, or upload your own file.
omat: bulk materials; oc20 or oc22: surfaces with adsorbates.
Al(100) slab with an adatom: the adatom (the highest atom) is chosen to start with. Click atoms to add or remove them, or upload your own structure.
The model is SaddleFlow FM2: a UMA-M-1.1 backbone with time conditioning and a per-atom flag, trained by flow matching on the MaterialsSaddles transition-state dataset (bulk materials, catalyst surfaces and battery materials). It moves the chosen atoms and lets the rest of the structure respond. A generated structure is a starting guess close to a saddle point. Refine runs Sella (first order, max force 0.01 eV/Å, up to 1000 steps or the demo's time limit) with UMA-S-1.2 on the chosen task; MEP displaces that saddle 0.2 Å along Sella's unstable mode both ways, minimizes each side with FIRE (max force 0.005 eV/Å) and checks each end for a remaining downhill direction, pushing on if it finds one. Weights: SciLM/SaddleFlow (revision fm2), released under the FAIR Chemistry License.