First Principles Calculation of Electron Impact Mass Spectrometry of Molecules

量子化学电子电离质谱(QCEIMS)程序结合了统计理论和Born-Oppenheimer分子动力学的原理，已经成功地应用于有机分子，最近还应用于有机金属化合物和主要基团无机分子。在第一个供资期间出版了六份与项目有关的出版物，简要介绍了这些出版物的情况。然后描述了QCEIMS方法内的当前技术状态。程序中引入了低成本半经验GFN-XTB哈密顿量，并给出了具体的技术细节。目前文献的概述，包括统计理论和相关分子动力学方法的最新发展，包含在与项目相关的出版物P4中，并考虑了对该项目的几个扩展。最重要的是，我们建议修改“QCEIMS”方法，使之适用于电喷雾电离/碰撞诱导解离质谱学(ESI/CID-MS)的模拟。我们列出了需要实施的必要步骤和方法。我们还计划将一个新的、专用的XTB版本参数化，用于快速计算电离势和电子亲和能，这是QCEIMS程序的关键一步。第三个要点是在大型实验质谱库上对计算的EI质谱图进行评估，重点是以前不能处理的非有机体系。QCEIMS将继续应用于特殊的化学系统，以进一步确立QCEIMS作为理论化学和质谱学的常规工具。

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.