ChargeFlow dataset release: training source corpora, split manifests, and external periodic benchmark

Dataset release accompanying the manuscript ChargeFlow: Flow-Matching Refinement of Charge-Conditioned Electron Densities. The package contains two Materials Project source-corpus archives used to define the manuscript training and internal-development-holdout splits, sanitized split manifests that map exact paper samples onto archive members, and an external periodic benchmark spanning perovskites, charged defects, multisite and special diamond defects, MOFs, extreme MOFs, organic crystals, and extreme organic crystals. The package-level README, archive inventory, and split manifests describe how the archives are organized. The internal development hold-out split is included for reproducibility of model development and is not the manuscript's external benchmark for out-of-distribution evaluation.