First-principle calculations of the structural, vibrational, mechanical, electronic, and optical properties of ε-O8 under pressure

• Published in: Journal of molecular modeling Vol. 28; no. 11; p. 360
• Main Authors: Bao, Shi-Yuan, Hong, Dan, Lu, Yi-Chen, Liu, Qi-Jun, Liu, Zheng-Tang, Zhang, Jian-Qiong
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2022; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Dispersion curve analysis; dispersions; Energy gap; exhibitions; First principles; Mathematical analysis; methodology; Molecular Medicine; Optical properties; Original Paper; phase transition; Phase transitions; Theoretical and Computational Chemistry; Unit cell; Mechanical properties; Electronic properties; Optical properties; O; High pressure
• ISSN: 1610-2940; 0948-5023; 0948-5023
• DOI: 10.1007/s00894-022-05352-z

The vibrational, mechanical, electronic, and optical properties of the ε -O 8 phase in the pressure range of 11.4–70 GPa were studied by the first-principle calculation method. The phonon dispersion curves have a tiny virtual frequency at 60 GPa, which indicates that ε -O 8 is dynamically unstable at 60 GPa. However, the 3-BM EOS demonstrates that the unit cell is stable up to 70 GPa. It has been shown that ε -O 8 remains ductile within the whole applied pressure range. Concurrently, we calculated the variation of the band gap of ε -O 8 in the pressure range of 11.4–70 GPa. The results show that the band gap of ε -O 8 decreases with increasing pressure. Notably, the band gap disappears within the range of 50–60 GPa, which reveals that the metallic phase transition occurs within this pressure range.