Red and blue shift of liquid water’s excited states: A many body perturbation study
Red and blue shift of liquid water’s excited states: A many body perturbation study
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液态水激发态的红移和蓝移：多体微扰研究
DOI：
10.1063/1.4960561
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发表时间：
2016
影响因子：
4.4
通讯作者：
T. Bredow
中科院分区：
文献类型：
--
作者：
Vafa Ziaei;T. Bredow
本文用多体微扰法计算了液态水在5-20 eV能量范围内的精确吸收光谱，以探讨水的激发态性质。最近的非弹性X射线测量的主要特点是很好地再现，如在7.9 eV的束缚激子峰与肩在9.4 eV，以及在13.9 eV的吸收最大值，其次是在18.4 eV的宽肩。该光谱由激子效应主导，激子效应在低能量和高能量状态下影响光谱的结构，混合有高能量下的单粒子效应。激子分布的低能量状态，特别是S1，是高度各向异性和本地化主要是在一个水分子。S1态本质上是HOCO-LUCO（最高占据晶体轨道-最低未占据晶体轨道）跃迁，属于分子内型，具有定域价态特征。当激发能增加时，晶体的性质发生了显著的变化。
In the present paper, accurate optical absorption spectrum of liquid H2O is calculated in the energy range of 5–20 eV to probe the nature of water’s excited states by means of many body perturbation approach. Main features of recent inelastic X-ray measurements are well reproduced, such as a bound excitonic peak at 7.9 eV with a shoulder at 9.4 eV as well as the absorption maximum at 13.9 eV, followed by a broad shoulder at 18.4 eV. The spectrum is dominated by excitonic effects impacting the structures of the spectrum at low and higher energy regimes mixed by single particle effects at high energies. The exciton distribution of the low-energy states, in particular of S1, is highly anisotropic and localized mostly on one water molecule. The S1 state is essentially a HOCO-LUCO (highest occupied crystal orbital - lowest unoccupied crystal orbital) transition and of intra-molecular type, showing a localized valence character. Once the excitation energy is increased, a significant change in the character of t...