First Principles Calculation of Electron Impact Mass Spectrometry of Molecules

量子化学电子电离质谱（QCEIMS）计划，如在原始提案中已经详细说明的那样，将统计理论的元素与Born-Oppenheimer分子动力学相结合，已成功应用于有机分子，最近还应用于有机金属化合物和主族无机分子。在第一个供资期间，出版了六份与项目有关的出版物，现对其作简要介绍。然后描绘了QCEIMS方法中的当前技术水平。具有成本效益的半经验GFN-xTB哈密顿量已被纳入程序，并列出了技术细节。当前文献的概述，包括统计理论和相关分子动力学方法的最新发展，包含在项目相关出版物P4中。最重要的是，我们建议修改“QCEIMS”的方法，以适合电喷雾电离/碰撞诱导解离质谱（ESI/CID MS）的模拟。我们制定了需要实施的必要步骤和方法。我们还计划参数化一个新的，特殊用途的xTB版本的快速计算电离势和电子亲和势，这是QCEIMS程序的关键一步。第三个要点是评估计算EI质谱的大型实验质谱数据库，重点是非有机系统，以前不能处理。将继续应用于特殊化学系统，以进一步建立QCEIMS作为理论化学和质谱分析的常规工具。

The Quantum Chemistry Electron Ionization Mass Spectra (QCEIMS) program, which as already detailed in the original proposal, combines elements of statistical theory with Born-Oppenheimer Molecular dynamics, has been successfully applied to organic molecules, and very recently to organometallic compounds and main group inorganic molecules. Six project-related publications have appeared during the first funding period, which are described briefly. The current state of the art within the QCEIMS method is then portrayed. The cost-efficient semi-empirical GFN-xTB Hamiltonian has been incorporated into the program, and the technical details are laid out. An overview of the current literature, including recent developments in statistical theory and related molecular dynamics approaches, is contained in project-related publication P4.Several extensions to the project are considered. Most importantly, we propose to modify the "QCEIMS" methodology to be suitable for the simulation of Electrospray Ionization/ Collision Induced Dissociation Mass Spectrometry (ESI/CID MS). We lay out the necessary steps and methodology that needs to be implemented. We also plan to parametrize a new, special-purpose xTB version for the fast computation of ionization potentials and electron affinities, which is a crucial step of the QCEIMS procedure. A third major point is the evaluation of computed EI mass spectra on a large experimental mass spectral database with some emphasis on non-organic systems which previously could not be treated. Applications to special chemical systems will be continued to establish QCEIMS further as a routine tool in theoretical chemistry and mass spectrometry.