Total energy calculation of high pressure selenium: The origin of incommensurate modulations in Se-IV and the instability of proposed Se-II
arXiv:cond-mat/0408539 · doi:10.1088/0953-8984/17/12/009
Abstract
We present calculation of the high pressure crystal structures in selenium, including rational approximants to the recently reported incommensurate phases. We show how the incommensurate phases can be intuitively explained in terms of imaginary phonon frequencies arising from Kohn anomalies in the putative undistorted phase. We also find inconsistencies between the calculated and experimental Se-II phase - the calculations show it to be a metastable metal while the experiment finds a stable semiconductor. We propose that the experimentally reported structure is probably in error.
arXiv comment4 pages 4 figures
References in corpus (5)
- Phonons and related properties of extended systems from density-functional perturbation theory
- quasiharmonic equations of state for dynamically-stabilized soft-mode materials
- Origin of complex crystal structures of elements at pressure
- Theoretical and computational study of high pressure structures in barium
- Comparison of structural transformations and superconductivity in compressed Sulfur and Selenium