OpenCitations Meta Database Dump

Compared to the previous version, this release includes metadata related to citing and cited bibliographic resources added from the February 2026 version of Crossref (https://api.crossref.org/snapshots/monthly/2026/02/all.json.tar.gz) and the August 2025 version of JaLC (https://api.japanlinkcenter.org/). It also includes an alignment with OpenAlex identifiers (https://openalex.s3.amazonaws.com/browse.html). Moreover, this version introduces two new sources: OUTCITE (https://doi.org/10.5281/zenodo.18172742) and Matilda (https://matilda.science). This dataset contains a full dump of the OpenCitations Meta Virtuoso database. It includes bibliographic metadata for all publications in the OpenCitations Index. This version of the dataset contains:- 147,369,096 bibliographic entities- 422,366,470 authors, 3,673,399 editors, and 115,504,540 publishers (counted by their roles, without disambiguating individual entities)- 2,302,011 publication venues- A full-text index for textual searches. The data is provided as a multi-part 7zip archive. The archive contains the Virtuoso database file (`database/virtuoso.db`) and the related Virtuoso configuration file (`database/virtuoso.ini`). To extract the archive, please use the provided extraction scripts (`extract_archive.sh` for Linux/macOS and `extract_archive.bat` for Windows). Usage example (Linux/macOS):`bash extract_archive.sh oc_meta_data_2026_06_27.7z.001 ./extracted_data`Usage example (Windows):`extract_archive.bat oc_meta_data_2026_06_27.7z.001 .\extracted_data` The compressed archives total ~30G, using the 7-zip compression algorithm, and expand to ~187G when decompressed on an ext4 filesystem. For more information, please refer to the following paper: Arcangelo Massari, Fabio Mariani, Ivan Heibi, Silvio Peroni, David Shotton; OpenCitations Meta. Quantitative Science Studies 2024; 5 (1): 50–75. doi: https://doi.org/10.1162/qss_a_00292