Ibis

Ibis is a flow-matching model that generates conformational ensembles of proteins at Cα resolution from their amino acid sequence. It is the model studied in Ablating Design Choices for Protein Ensemble Generators Across Structural Regimes (Quinn & Bent, 2026).

Checkpoints

File	In the paper	Training data for disordered proteins
base/model.ckpt	Base	CALVADOS coarse-grained simulations
mix/model.ckpt	Fragment 50%	half CALVADOS simulations, half IDRome-o fragment-assembled ensembles

Both models are also trained on AlphaFold DB structures of folded proteins and on CALVADOS simulations of multi-domain proteins. They take sequences of up to 510 residues. In the paper's evaluation against experimental data, mix agreed better with NMR chemical shifts and slightly worse with SAXS than base.