We developed a quantum-chemical approach for ab initio calculations of metastable-induced electron-emission spectra (MIES). In contrast to earlier work, our calculation method accounts for the anisotropy of the MIES spectra with respect to not only the direction of incidence of metastable helium but also to that of electron detection. Since we can freely choose both, incidence and detection direction in our simulation, our method is able to reconstruct MIES spectra which are dominated by Auger deexcitation for any experimental setups and orientation of the studied molecules. Here, we study the dependence of the MIES spectrum on the incidence and detection direction and other experimental parameters and compare the results for the case of adsorbed benzene with experimental data.

我们开发了一种量子化学方法，用于从头计算亚稳态感应电子发射光谱（MIES）。与早期的工作相比，我们的计算方法不仅考虑了MIES谱的各向异性，而且还涉及了亚稳态氦的入射方向以及电子检测的各向异性。由于我们可以在模拟中自由选择入射方向和检测方向，因此我们的方法能够重建MIES光谱，该光谱对于任何实验设置和所研究分子的取向都以俄歇（Auger）激发为主导。在这里，我们研究了MIES光谱对入射和检测方向以及其他实验参数的依赖性，并将吸附苯的结果与实验数据进行了比较。