Acknowledgements: T. C. and B. K. acknowledge support from the UK Engineering and Physical Sciences Research Council (EPSRC) through the Early Career Fellowship grant (EP/T026138/1). T. C. further acknowledges fruitful discussions with Benedict Saunders and Huseyin Sener Sen. B. M. acknowledges support from a UKRI Future Leaders Fellowship (MR/V023926/1), from the Gianna Angelopoulos Programme for Science, Technology, and Innovation, and from the Winton Programme for the Physics of Sustainability. A. T. and R. I. W. thank Companhia Brasileira de Metalurgia e Mineração (CBMM) for funding. Computing facilities were provided by the Scientific Computing Research Technology Platform (SCRTP) at the University of Warwick. DFT calculations were performed using the Avon, Sulis and Orac HPC platforms, and Sulis is funded by the EPSRC Grant (EP/T022108/1) and the HPC Midlands+ consortium. Part of the calculations were performed using resources provided by the Cambridge Tier-2 system (operated by the University of Cambridge Research Computing Service and funded by EPSRC [EP/P020259/1]).