Ab Initio Study of the Dynamical Si-O Bond Breaking Event in α-Quartz

作者：Su Rui; Zhang Hong; Han Wei; Chen Jun^*

来源：Chinese Physics Letters, 2015, 32(10): 107803.

DOI：10.1088/0256-307X/32/10/107803

• AUGMENTED-WAVE METHOD
• MOLECULAR-DYNAMICS
• SILICA
• BAND
• CENTERS
• GLASS

The Si-O bond breaking event in the alpha-quartz at the first triplet (T-1) excitation state is studied by using ab initio molecular dynamics (AIMD) and nudged elastic band calculations. A meta-stable non-bridging oxygen hole center and E' center (NBOHC-E') is observed in the AIMD which consists of a broken Si-O bond with a Si-O distance of 2.54 angstrom. By disallowing the re-bonding of the Si and O atoms, another defect configuration (III-Si/V-Si) is obtained and validated to be stable at both ground and excitation states. The NBOHC-E' is found to present on the minimal energy pathway of the initial to III-Si/V-Si transition, showing that the generating of the NBOHC-E' is an important step of the excitation induced structure defect. The energy barriers to produce the NBOHC-E' and III-Si/V-Si defects are calculated to be 1.19 and 1.28 eV, respectively. The electronic structures of the two defects are calculated by the self-consistent GW calculations and the results show a clear electron transition from the bonding orbital to the non-bonding orbital.

• 出版日期2015-10
• 单位中国工程物理研究院激光聚变研究中心; 北京应用物理与计算数学研究所; 北京大学; 四川大学