Paper

{
  "raw_xml": "<entry>\n    <id>http://arxiv.org/abs/2602.24248v1</id>\n    <title>Resolving the Metastable Si-XIII Structure through Convergent Theory and Experiment</title>\n    <updated>2026-02-27T18:20:33Z</updated>\n    <link href='https://arxiv.org/abs/2602.24248v1' rel='alternate' type='text/html'/>\n    <link href='https://arxiv.org/pdf/2602.24248v1' rel='related' title='pdf' type='application/pdf'/>\n    <summary>Silicon is the undisputed cornerstone of modern technology, with applications ranging from micro- and opto-electronics to quantum technologies. Recently, the exploration of its allotropes has emerged as a pivotal frontier for engineering materials with tailored optical and electronic functionalities. High-pressure experiments have revealed several metastable silicon phases, among which is Si-XIII. First observed more than 20 years ago, this phase has remained structurally unidentified, representing a significant gap in our understanding of elemental silicon allotropy. In this work, a convergent methodology is employed combining advanced theoretical modeling with experimental characterization to finally resolve the long-standing structural assignment of Si-XIII. Guided by careful experimental observations, a structural model validated through first-principles optimization and systematically tested against multiple experimental signatures is constructed. All the fingerprints of this phase are rationalized by our proposed crystal structure: interplanar spacings, Raman frequencies, thermodynamic stability, and kinetic pathways. These findings provide a crucial missing piece in the high-pressure phase diagram of silicon and demonstrate the power of integrating computational predictions with experimental validation to resolve complex structural problems in materials science.</summary>\n    <category scheme='http://arxiv.org/schemas/atom' term='cond-mat.mtrl-sci'/>\n    <category scheme='http://arxiv.org/schemas/atom' term='physics.app-ph'/>\n    <category scheme='http://arxiv.org/schemas/atom' term='physics.comp-ph'/>\n    <published>2026-02-27T18:20:33Z</published>\n    <arxiv:primary_category term='cond-mat.mtrl-sci'/>\n    <author>\n      <name>Fabrizio Rovaris</name>\n    </author>\n    <author>\n      <name>Corrado Bongiorno</name>\n    </author>\n    <author>\n      <name>Anna Marzegalli</name>\n    </author>\n    <author>\n      <name>Mouad Bikerouin</name>\n    </author>\n    <author>\n      <name>Davide Spirito</name>\n    </author>\n    <author>\n      <name>Gerald J. K. Schaffar</name>\n    </author>\n    <author>\n      <name>Mohamed Zaghloul</name>\n    </author>\n    <author>\n      <name>Agnieszka Anna Corley-Wiciak</name>\n    </author>\n    <author>\n      <name>Francesco Montalenti</name>\n    </author>\n    <author>\n      <name>Verena Maier-Kiener</name>\n    </author>\n    <author>\n      <name>Giovanni Capellini</name>\n    </author>\n    <author>\n      <name>Antonio M. Mio</name>\n    </author>\n    <author>\n      <name>Emilio Scalise</name>\n    </author>\n  </entry>"
}