Relativistic calculations of photoionization cross-section of Mg-like Ca IX Narendra Kumar, Shivankar, Dishu Dawra, Mayank Dimri, Man Mohan and Alok Kumar Singh Jha Eur. Phys. J. Plus, 139 10 (2024) 929 Published online: 24 October 2024 DOI: 10.1140/epjp/s13360-024-05716-9