3D Molecule Generation from Rigid Motifs via $\mathrm{SE}(3)$ Flows

Three-dimensional molecular structure generation is typically performed at the level of individual atoms, yet molecular graph generation techniques often consider *fragments* as their structural units. Building on the advances in *frame-based* protein structure generation, we extend these fragmentation ideas to 3D, treating general molecules as sets of *rigid-body motifs*. Utilising this representation, we employ $\mathrm{SE}(3)$-equivariant generative modelling for *de novo* 3D molecule generation from rigid motifs. In our evaluations, we observe comparable or superior results to state-of-the-art across benchmarks, surpassing it in atom stability on GEOM-Drugs, while yielding a $2\times$ to $10\times$ reduction in generation steps and offering $3.5\times$ compression in molecular representations compared to the standard atom-based methods.