Universal Electronic‐Structure Relationship Governing Intrinsic Magnetic Properties in Permanent Magnets

An electronic‐structure‐centered perspective is presented on permanent‐magnet (PM) design, highlighting two key levers, that is, saturation magnetization ( M s ), governed by 3d ‐band filling and exchange physics, and magnetocrystalline anisotropy energy (MAE), arising from spin‐orbit coupling (SOC) on anisotropic orbital populations. Reviewing current practices, including DFT‐based MAE/ J ij extraction, atomistic‐spin and micromagnetic modeling, and high‐throughput machine learning (ML) pipelines, three bottlenecks limiting predictive discovery is identified that is i) electronic‐structure accuracy for small MAE (sensitive to functional choice, Hubbard U , and many‐body effects), ii) finite‐temperature and kinetic realism (phonon/magnon renormalization, ordering kinetics), and iii) descriptor and multiscale decoupling (lack of SOC‐weighted and orbital‐resolved fingerprints). Deep dives into the electronic‐structure of Nd─Fe─B and Fe─N show how these fingerprints govern magnetic performance, motivating DFT‐ and quantum‐mechanics‐based descriptors for discovery. Unbiased, structure‐driven exploration, coupled with high‐throughput simulations, ML, generative AI, and reasoning models, accelerates candidate identification and propagates insights across scales. Addressing supply‐chain risks, on future needs of designing “critical‐element‐free” magnets with tailored microstructure and high energy products is emphasized. By integrating electronic fingerprints, AI reasoning, and multiscale modeling, a practical roadmap is provided for rare‐earth‐lean or rare‐earth free, high‐performance, sustainable PMs.