A low-order scaling incremental correlation method for the calculation of electronic excitation energies

波函数方法至今仍是研究分子中电子激发的最可靠的方法。然而，其高规模的计算成本是一个可怕的障碍，在扩展系统中的应用。在这个项目中，我们建议发展一类近似法，以便在轨道增量的基础上进行这种计算。这种方法具有固有的优点，它可以很容易地推广到一个大家庭的电子结构方法。通过使用截断占用和虚拟空间，我们的目标是实现相对于系统大小的计算成本的渐近次线性缩放。本研究的结果将应用于常见的生物分子辅因子的吸收光谱的计算。我们将定量评估不同化学环境对光谱主要特征的影响。这些信息对于通过体外紫外-可见光谱鉴定活性中间体是非常宝贵的。

Wave function methods are still to date the most reliable approach to the study of electronic excitations in molecules. However, their high scaling computational cost is a terrific obstacle for the application in extended systems. In this project, we propose the development of a class of approximations to carry out such calculations on the basis of orbital increments. This approach has the inherent advantage that it can be easily generalized for a large family of electronic structure methods. Through the use of truncated occupied and virtual spaces, we will aim to achieve an asymptotic sub-linear scaling of computational cost relative to the system size. The results of this study will be applied to the calculation of absorption spectra in common biomolecular cofactors. We will quantitatively assess the impact of different chemical environments in the dominant features of their spectra. Such information is invaluable for the identification of reactive intermediates through in vitro UV-Vis spectroscopy.