This dataset contains numerical simulations of bottom-heated, top-heavy double-diffusive geodynamo models in a rotating spherical shell. These models are designed to investigate geomagnetic signatures of possible stratified regions near the top of Earth’s outer core. The simulations span a range of thermal and compositional forcings, enabling the study of how lower-mantle heterogeneities and light element accumulation driven stratification may influence the geomagnetic field. The dataset provides: 1. Simulation state files (final state and time-averaged state) in NetCDF format. Due to the large size of full state outputs, only these two files are included. 2. Time-series outputs of key dynamical variables. 3. Post-processed diagnostic quantities, including spatial and temporal averages, kinetic energy budgets, forces relevant to double-diffusive dynamics [2], and metrics used to assess possible thermally and/or compositionally stratified layers near the core–mantle boundary. 4. Metrics to compare the simulation outputs with the features of geomagnetic field over various timescales. All simulations were produced using the Leeds Spherical Dynamo Code [3] and run on the ARCHER2 high-performance computing system. References [1] https://doi.org/10.48550/arXiv.2507.03538 [2] https://doi.org/10.1017/jfm.2025.259 [3] https://github.com/Leeds-Spherical-Dynamo/leeds-spherical-dynamo