It is worth noting that when dealing with complex large fragments assembled OOMs, the baseline models have difficulty converging within a limited time. For generating 10,000 molecules, the inference times of EDM, GeoLDM, and GeoBFN for generating molecules are as high as 42.40 h, 41.57 h, and 32.17 h, respectively; while the inference time of O 2 -GEN is only 1.3 h. This demonstrates the rapidity and efficiency of O 2 -GEN in handling such systems.