Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany.
J Chem Phys. 2011 Jan 14;134(2):024106. doi: 10.1063/1.3523982.
Excited states of atoms and molecules lying above the ionization threshold can decay by electron emission in a process commonly known as autoionization. The autoionization widths can be calculated conveniently using Fano formalism and discretized atomic and molecular spectra by a standard procedure referred to as Stieltjes imaging. The Stieltjes imaging procedure requires the use of the full discretized spectrum of the final states of the autoionization, making its use for poly-atomic systems described by high-quality basis sets impractical. Following our previous work on photoionization cross-sections, here we show that also in the case of autoionization widths, the full diagonalization bottleneck can be overcome by the use of Lanczos pseudospectra. We test the proposed method by calculating the well-documented autoionization widths of inner-valence-excited neon and apply the new technique to autoionizing states of hydrofluoric acid and benzene.
处于电离阈之上的原子和分子的激发态可以通过电子发射而衰减，这一过程通常被称为自电离。自电离宽度可以使用 Fano 形式理论和离散化的原子和分子谱方便地计算，这一过程被称为斯蒂尔杰斯成像。斯蒂尔杰斯成像过程需要使用自电离末态的完整离散谱，这使得它对于由高质量基组描述的多原子系统的应用变得不切实际。在我们之前关于光电离截面的工作之后，我们在这里表明，在自电离宽度的情况下，也可以通过使用 Lanczos 伪谱来克服全对角化瓶颈。我们通过计算已被很好地记录的内价层激发氖的自电离宽度来测试所提出的方法，并将新技术应用于氢氟酸和苯的自电离态。
