论文标题
通过耦合集群green的功能来构建“全频”光谱
Constructing `full-frequency' spectra via moment constraints for coupled cluster Green's functions
论文作者
论文摘要
我们提出了一种通过保存一组静态期望值来构建“全频”准粒子光谱的方法。这些期望值定义了光谱分布的力矩，从而导致了有效且系统地改进的扩展。通过在耦合群集水平上计算这些初始力矩约束，我们在相关状态特异性和完整光谱量中都表明了收敛性，同时需要传统绿色功能方法的努力的一部分。经过用于带电激发光谱的GW100基准测试，我们可以将边界激发收敛到CCSD近似固有的精度之内，同时在所有能量量表上同时获得整个激发光谱的同时表示。
We propose an approach to build `full-frequency' quasiparticle spectra from conservation of a set of static expectation values. These expectation values define the moments of the spectral distribution, resulting in an efficient and systematically improvable expansion. By computing these initial moment constraints at the coupled-cluster level, we demonstrate convergence in both correlated state-specific and full spectral quantities, while requiring a fraction of the effort of traditional Green's function approaches. Tested across the GW100 benchmark set for charged excitation spectra, we can converge frontier excitations to within the inherent accuracy of the CCSD approximation, whilst obtaining a simultaneous representation of the entire excitation spectrum at all energy scales.
