Vibrational and structural properties of P 2 O 5 glass: Advances from a combined modeling approach
Vibrational and structural properties of P 2 O 5 glass: Advances from a combined modeling approach
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P 2 O 5 玻璃的振动和结构特性：组合建模方法的进展
DOI：
10.1103/physrevb.100.134309
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发表时间：
2019
影响因子：
3.7
通讯作者：
Shcheblanov N
中科院分区：
文献类型：
--
作者：
Shcheblanov N
我们给出了晶体和非晶相的实验测量和从头算模拟。计算的拉曼光谱、红外光谱和振动态密度(VDOS)光谱与实验测量结果符合得很好，并包含了非晶相所有特殊的局部结构的特征，即桥联和非桥联(双键或末端)氧以及与物种相关的四面体单元(表示各种类型的四面体，以及连接四面体和网络其余部分的桥式氧原子的数量)。为了揭示振动光谱的内在结构，利用基于对称群的模式投影法研究了不同频率范围内振动模式的特性。特别是，在870-870范围内的VDOS谱主要是与氧和磷(带)原子桥联有关的弯曲()运动，而高频双重区(-1250)主要与不对称()和对称()伸缩模式有关，最显著的峰在1400(exp.1380)主要是由于双键氧原子支撑的不对称伸缩振动。低于600的较低频率范围显示为弯曲(和)和旋转()模式的混合。剪刀型弯曲()和旋转()模在600以下很好地局部化，而弯曲模扩展到-870范围。本征模到和物种上的投影在与拉曼和红外波段的位置惊人地对应的频率上产生了明确的贡献。
We present experimental measurements andab initiosimulations of the crystalline and amorphous phases of. The calculated Raman, infrared, and vibrational density of states (VDOS) spectra are in excellent agreement with experimental measurements and contain the signatures of all the peculiar local structures of the amorphous phase, namely, bridging and nonbridging (double-bonded or terminal) oxygens and tetrahedralunits associated with, andspecies (denotes the various types oftetrahedra, withbeing the number of bridging oxygen atoms that connect the tetrahedra to the rest of the network). In order to reveal the internal structure of the vibrational spectrum, the characteristics of vibrational modes in different frequency ranges are investigated using a mode-projection approach at different symmetries based on thesymmetry group. In particular, the VDOS spectrum in the range fromto 870is dominated by bending () motions related to bridging oxygen and phosphorus (band) atoms, while the high-frequency doublet zone (–1250) is associated mostly with the asymmetric () and symmetric () stretching modes, and most prominent peak around 1400(exp. 1380) is mainly due to asymmetric stretching vibrations supported by double-bonded oxygen atoms. The lower-frequency range below 600is shown to arise from a mixture of bending (and) and rotation () modes. The scissors bending () and rotation () modes are well localized below 600, whereas thebending modes spread further into the range–870. The projections of the eigenmodes onto, andspecies yield well-defined contributions at frequencies in striking correspondence with the positions of the Raman and infrared bands.