biostudies-literatureSun YACS | American Chemical Society Petroleum Research FundACS | American Chemical Society Petroleum Research Fund (PRF)DOE Office of Science Office of Fusion Energy SciencesNational Science Foundation (NSF)DOE | NNSA | Office of Defense ProgramsNational Science Foundatione2218405120https://www.ebi.ac.uk/biostudies/studies/S-EPMC9974499biostudies-literatureUnknown120(8)Most metals adopt simple structures such as body-centered cubic (BCC), face-centered cubic (FCC), and hexagonal close-packed (HCP) structures in specific groupings across the periodic table, and many undergo transitions to surprisingly complex structures on compression, not expected from conventional free-electron-based theories of metals. First-principles calculations have been able to reproduce many observed structures and transitions, but a unified, predictive theory that underlies this behavior is not yet in hand. Discovered by analyzing the electronic properties of metals in various lattices over a broad range of sizes and geometries, a remarkably simple theory shows that the stability of metal structures is governed by electrons occupying local interstitial orbitals and their strong chemical interactions. The theory provides a basis for understanding and predicting structures in solid compounds and alloys over a broad range of conditions.Proceedings of the National Academy of Sciences of the United States of AmericaChemical interactions that govern the structures of metals.PMC9974499DMR-2104881DE-SC0020340DMR 1848141ACS PRF 50249-UNI6DE-NA0003975OAC 2117956Zheng YZhao LHemley RJPickard CJSun YMiao MfalseChemical interactions that govern the structures of metals.Most metals adopt simple structures such as body-centered cubic (BCC), face-centered cubic (FCC), and hexagonal close-packed (HCP) structures in specific groupings across the periodic table, and many undergo transitions to surprisingly complex structures on compression, not expected from conventional free-electron-based theories of metals. First-principles calculations have been able to reproduce many observed structures and transitions, but a unified, predictive theory that underlies this behavior is not yet in hand. Discovered by analyzing the electronic properties of metals in various lattices over a broad range of sizes and geometries, a remarkably simple theory shows that the stability of metal structures is governed by electrons occupying local interstitial orbitals and their strong chemical interactions. The theory provides a basis for understanding and predicting structures in solid compounds and alloys over a broad range of conditions.2023-01-01T00:00:00Z2023 Feb2026-03-18T14:08:16.324Z2025-04-04T20:05:18.867ZS-EPMC99744993678736810.1073/pnas.2218405120