Theoretical predictions of two new chiral solid carbon oxides

Abstract

Two carbon oxides, termed as C6O9-154-6c6c3a and C6O9-154-6c6c3b, are theoretically predicted by first-principles calculations. Both structures belong to space group P3221, indicating that both are chiral structures. Both phonon spectra have no negative branches, certifying their dynamic stability. Both calculated elastic constants satisfy the criteria of mechanical stability. The ab initio molecular dynamics simulations reveal that both structures are not only room-temperature stable but also thermally stable even at 1000 K. The band structures demonstrate that both structures are indirect semiconductors. The C6O9-154-6c6c3a has a bandgap of 7.23 eV, while the bandgap of C6O9-154-6c6c3b is 8.82 eV. Simulated XRD features, Raman spectra, and vibration patterns are provided to help identify the future experimental samples. These two new chiral stable carbon oxides can not only provide more new chemical and physical properties about solid carbon oxides but also offer potential applications for carbon capture and utilization in the future.