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Abstract：
We demonstrate the importance of addressing the Γ vertex and thus going beyond the GW approximation for achieving the energy levels of liquid water in many-body perturbation theory. In particular, we consider an effective vertex function in both the polarizability and the self-energy, which does not produce any computational overhead compared with the GW approximation. We yield the band gap, the ionization potential, and the electron affinity in good agreement with experiment and with a hybrid functional description. The achieved electronic structure and dielectric screening further lead to a good description of the optical absorption spectrum, as obtained through the solution of the Bethe-Salpeter equation. In particular, the experimental peak position of the exciton is accurately reproduced.
摘要：
我们证明了在多体扰动理论中解决Γ顶点并因此超越GW近似以实现液态水能级的重要性。特别是,我们考虑了极化率和自能量的有效顶点函数，与GW近似相比，这不会产生任何计算开销。我们产生带隙，电离电位，电子亲和力与实验和混合功能描述非常吻合。所实现的电子结构和介电屏蔽进一步导致对光学吸收光谱的良好描述，通过Bethe-Salpeter方程的解获得。特别是,准确再现了激子的实验峰位置。
