Ground- and excited-state properties of hydrogen-bonded water monomers studied by first-principles calculations

我们计划研究聚集态水分子的结构性质与它们的电子和光学激发之间的关系和相互作用。特别是，我们想要阐明一、二、三和四重氢键水单体的光学指纹和电子激发光谱与周围基质的关系。为此，对气相中的水团簇和一维水链、模拟固体和液态水的主体结构以及固体水的点缺陷和表面进行了计算。通过对计算光谱与实验的对比分析，可望大大有助于解决有关液态水结构性质的争论，并有助于理解水合电子的局域特性。计算分三个步骤进行：(I)原子和电子的基态性质是从广义梯度近似下的密度泛函理论计算得到的，以描述交换和关联。(Ii)在GW近似水平上计入电子自能；(Iii)根据Bethe-Salpeter方程的初值公式确定电子-空穴吸引效应。

We plan to study the relation and interplay between the structural properties of aggregated water molecules and their electronic and optical excitations. In particular, we want to clarify the optical fingerprints and electronic excitation spectra of one-, two-, three-, and four-fold hydrogen-bonded water monomers in dependence on the surrounding matrix. To that end, calculations are performed for water clusters and one-dimensional water chains in the gas-phase, bulk structures that model solid and liquid water as well as point defects and surfaces of solid water. The analysis of the calculated spectra in comparison with experiment is expected to help significantly to resolve the controversy on the structural properties of liquid water and in understanding the localisation characteristics of hydrated electrons. The proposed calculations proceed in three steps: (i) Atomic and electronic ground-state properties are obtained from density-functional theory calculations within the generalised gradient approximation to describe exchange and correlation. (ii) The electronic self-energy is included on the level of the GW approximation and (iii) electron-hole attraction effects are determined on the basis of an initial-value formulation of the Bethe-Salpeter equation.