The generator is inspired by the VD-GEN method . Virtual Particles (VPs) are uniformly initialized within a predefined space and iteratively moved to regions of high-probability atomic distribution (Figure .a). This movement is guided by the pre-trained 3D backbone. Depending on different application scenarios, the generator can utilize specific molecular structures as initial templates to define the sampling space. This helps the virtual particles converge more rapidly during iteration, enhancing the generation speed, validity, and functionality of OOMs. Such features also enable us to modify and regenerate any part of a specific molecule, demonstrating the high flexibility of the generator. Next, we will evaluate the performance across different datasets. To ensure a fair comparison among different models, we fine-tuned the generator on the corresponding datasets prior to evaluation. Generation task on fused-ring molecule databases The section demonstrates the framework's performance in generating novel and feasible fused-ring molecules. The framework was first tested on datasets like COMPAS-1X and PAS , which contain fused-ring molecules with medium size. Analysis of atomic length distributions shows COMPAS-1X containing cata-condensed polybenzenoid hydrocarbons (cc-PBHs) within a range of 12 to 72, and PAS displaying a range from 10 to 66 in heterocyclic structures. The atomic length distributions are available in Supplementary Figure . We benchmarked against GaUDI due to its state-of-the-art performance in generating polycyclic molecules using EDM and Graph of Rings (GOR) representations . To validate our framework, we generated 10,000 molecules per dataset using the OOMs generator, assessing them based on the following metrics : Validity (percentage of valid molecules as measured by RDKit ), Uniqueness (percentage of unique valid molecules), Novelty (percentage of valid molecules not in the training set), and V&U&N (the fraction of valid, unique and novel molecules that are not present in the training set) .