Si₁₀: A sp³ Silicon Allotrope with Spirally Connected Si₅ Tetrahedrons

Abstract

SUPPORTING INFORMATION ContentsCalculation Details.Supplementary Table 1: mechanical properties of Si 10 and Si-I. Supplementary Table 2: comparison of the calculated d-spacings of Si 10 with the observed values in the experiment. Supplementary Table 3: simulated electron diffraction data of Si 10 .Supplementary Figure 1: comparison of imaginary part of dielectric function and optical absorption coefficient of Si 10 with that of Si-I phase.Supplementary Figure 2: simulated electron diffraction patterns of Si 10 phase along a specific zone axis compared with the experimental data. Supplementary Figure 3: simulated electron diffraction patterns of Si 10 phase along different crystal zone axes compared with the experimental data.References.

First-Principles Study of the Adsorption and Depolymerization Mechanisms of Sodium Silicate on Iron Surfaces at High Temperature

“…In addition, there is a strong overlap between 3s and 3p orbitals of Si atoms and 2p orbitals from O atoms, indicating strong bonds between them. The great contribution of the Si 3s orbital is due to the fact that Si atoms are sp 3 -hybridized and have a tetrahedral configuration . The four sp 3 orbitals have one electron each, which overlaps with the 2p orbital of oxygen to form the covalent bond.…”

“…The great contribution of the Si 3s orbital is due to the fact that Si atoms are sp 3 -hybridized and have a tetrahedral configuration. 43 The four sp 3 orbitals have one electron each, which overlaps with the 2p orbital of oxygen to form the covalent bond. The result is consistent with the calculated bond angle, indicating that the O−Si−O angle is 109.49°( Table S1).…”

Universal Phase Transitions of AlB2-Type Transition-Metal Diborides

“…The first method involved “searching for existing structures.” The 11 existing structures reported from the experimental and theoretical studies of AlB 2 -type metal borides were as follows: the tetragonal structures α-TiB 2 type (SG, I 4 1 / amd ) and β-TiB 2 type (SG, P 4 2 / mmc ); the orthorhombic structures KHg 2 type (SG, Imma ), oP12 (SG, Pnma ), and oP6 (SG, Pmmn ); the hexagonal structures AlB 2 type (SG, P 6/ mmm ), hP12­(SG, P 6 3 / mmc ), and hP6 (SG, P 6 3 / mmc ); the monoclinic structure C2/m (SG, C2/m ); the rhombohedral structures hR18 (SG, R -3 m ) and hR9 (SG, R -3 m ) . The second method used the recently developed evolutionary and particle-swarm optimization algorithms for crystal-structure prediction, and the most stable structures were predicted using the CALYPSO codes. , Details of the search algorithms and their applications are described in previous reports. − …”

Theoretical prediction of a novel hexagonal narrow-gap silicon allotrope under high pressures

“…Under slow pressure release, Si-II transforms into Si-XII (R8) at pressures less than 8 GPa and Si-III (BC8) at pressures between 0 and 2 GPa. Heating Si-III at temperatures ranging from 200 to 600 • C will transform it into Si-IV (hexagonal diamond), and further annealing of Si-IV will eventually revert it back to Si-I [13,14]. In addition to these high-pressure phases, various metastable silicon phases under ambient pressure have also been reported, such as ST12 [15], BT8 [16], Si 136 [17], Si 24 [18], and others.…”