In version 1.2.8, using Pymatgen=2024.3.1 causes error "name 'Union' is not defined". Upgrading Pymatgen to 2024.11.13 solves the issue.
In version 1.2.8, using Pymatgen=2024.3.1 causes error "name 'Union' is not defined". Upgrading Pymatgen to 2024.11.13 solves the issue.