Study Of Dft Methods For The Prediction Of Electron Detachment Energies Based On Anion Clusters

Electron detachment behavior is one of the key intrinsic properties for widespread anionic clusters.Usually,a quantitatively accurate characterization of electron detachment energy requires the combined effects of developing both high-precision experimental techniques and high-level theoretical tools.From the perspective of theoretical simulation,the search for efficient and reliable system of theory methods to predict anionic electron detachment and simulate the experimental photoelectron spectroscopy is of great significance.In this work,we assess the ability of different density functional theory(DFT)methods to reproduce the VDEs/ADEs of a series of 40 anions systematically.The statistical analysis of errors is performed by comparing the theoretical values with the experimental benchmark data obtained from the negative ion photoelectron spectroscopy(NIPES).First,the default?B97XD,MN15,CAM-B3LYP,DSD-PBEP86 and the proposed optimally tuned range-separated(OTRS)LC-?PBE*and?B97XD*functionals are recommended as the top six methods for accurate description of VDEs/ADEs.Interestingly,the proposed optimally tuned range-separated(OTRS)LC-?PBE*and?B97XD*functionals can not only well reproduce the experimental VDEs/ADEs,but also give accurate approximation by using the negative highest occupied molecular orbital energies(-?_H)to represent the VDEs.Further,the good performance of OTRS method is found to simulate experimental NIPES.In addition,the performances of the high-level IP-EOM-DLPNO-CCSD method are also evaluated for comparison.Further,to attribute the performance of various DFT methods,the delocalization error is quantified by calculation of energies of a multiply Charged Anions(MCA)B₁₂F₁₂^2-as a function of fractional electron numbers.Last,a reliable quasilinear fitting model based on the radius of the spherically symmetric average electron localization function(ELF)region of anions is proposed to efficiently obtain the OTRS parameters.The present work aims at assessing the ability of DFT methods and providing a reliable theoretical tool and fundamental understanding of electronic structures and electron detachment properties of various anionic systems.This paper is composed of four chapters,the specific content is as follows:Chapter 1:the important research significance of anion clusters and electron detachment energy and the research status at home and abroad are introduced,and the main work and innovation points of this paper are summarized.Chapter 2:the importance of the development and content of density functional method are summarized.The optimally tuned range-separated functional theory method is introduced,and its theoretical basis and development process are introduced in detail.Chapter 3:we assess the ability of 13 different density functional theory(DFT)methods to reproduce the VDEs/ADEs/-?_H of a series of 40 anions.The statistical analysis of errors is performed by comparing the theoretical values with the experimental benchmark data.The delocalization error of anions is quantified by calculation of energies of a MCA as a function of fractional electron numbers.And a reliable model is proposed to efficiently obtain the OTRS parameters ?*.Chapter 4:summarize the above research contents and results,and look forward to the next step.