论文标题
过滤大量过滤，以有效地扩展密度投影操作员
Gapped-filtering for efficient Chebyshev expansion of the density projection operator
论文作者
论文摘要
我们开发了间隙过滤的方法，从而，简短的Chebyshev扩展准确地代表了密度 - 矩阵操作员。该方法优化了Chebyshev系数，以在所有能量的所有能量下给出正确的密度矩阵，除了没有特征态的间隙区域内。与传统的扩展方法相比，Gapped Offlivering可以减少Chebyshev扩展中所需项的数量，只要人们知道或可以有效地确定HOMO和LUMO位置。当寻求高精度时，减少尤其明显（2-3的因素）。为了举例说明该方法，我们使用间隙过滤来提高随机GW计算的效率。
We develop the gapped-filtering method, whereby a short Chebyshev expansion accurately represents the density-matrix operator. The method optimizes the Chebyshev coefficients to give the correct density matrix at all energies except within the gapped region where there are no eigenstates. Gapped filtering reduces the number of required terms in the Chebyshev expansion compared to traditional expansion methods, as long as one knows or can determine efficiently the HOMO and LUMO positions. The reduction is especially noticeable (factors of 2-3) when high accuracy is sought. To exemplify the method, we use gapped-filtering to increase the efficiency of stochastic-GW calculations.
