Superconductivity and strong anharmonicity in novel Nb-S phases

Roman Lucrezi, Christoph Heil*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


In this work we explore the phase diagram of the binary Nb-S system from ambient pressures up to 250 GPa using ab initio evolutionary crystal structure prediction. We find several new stable compositions and phases, especially in the high-pressure regime, and investigate their electronic, vibrational, and superconducting properties. Our calculations show that all materials, besides the low-pressure phases of pure sulfur, are metals with low electron-phonon (ep) coupling strengths and critical superconducting temperatures below 15 K. Furthermore, we investigate the effects of phonon anharmonicity on lattice dynamics, ep interactions, and superconductivity for the novel high-pressure phase of Nb2S, demonstrating that the inclusion of anharmonicity stabilizes the lattice and enhances the ep interaction.

Original languageEnglish
Article number174001
JournalJournal of Physics Condensed Matter
Issue number17
Publication statusPublished - Apr 2021


  • ab initio materials design
  • electron-phonon interaction
  • phase diagram and structure prediction
  • phonon anharmonicity
  • superconductivity

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

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