Ionic liquids play an important role in many technological applications and a detailed understanding of their frontier molecular orbitals is required to optimize interfacial barriers,reactivity and stability with resp...Ionic liquids play an important role in many technological applications and a detailed understanding of their frontier molecular orbitals is required to optimize interfacial barriers,reactivity and stability with respect to electron injection and removal.In this work,we calculate quasiparticle energy levels of ionic liquids using first-principles many-body perturbation theory within the GW approximation and compare our results to various mean-field approaches,including semilocal and hybrid density-functional theory and Hartree-Fock.We find that the mean-field results depend qualitatively and quantitatively on the treatment of exchange-correlation effects,while GW calculations produce results that are in excellent agreement with experimental photoelectron spectra of gas phase ion pairs and ionic liquids.These results establish the GW approach as a valuable tool for understanding the electronic structures of ionic liquids.展开更多
基金J.M.K.and J.L.acknowledge support from EPRSC under Grant No.EP/R002010/1 and from a Royal Society University Research Fellowship(URF\R\191004)Via J.L.’s membership of the UK’s HEC Materials Chemistry Consortium,which is funded by EPSRC(EP/L000202)+1 种基金I.K.and V.K.acknowledge Estonian Centre of Excellence in Research project“Advanced materials and high-technology devices for sustainable energetics,sensorics and nanoelectronics”TK141(2014-2020.4.01.15-0011)K.R.J.L.acknowledges support from a Royal Society University Research Fellowship(URF\R\150353).
文摘Ionic liquids play an important role in many technological applications and a detailed understanding of their frontier molecular orbitals is required to optimize interfacial barriers,reactivity and stability with respect to electron injection and removal.In this work,we calculate quasiparticle energy levels of ionic liquids using first-principles many-body perturbation theory within the GW approximation and compare our results to various mean-field approaches,including semilocal and hybrid density-functional theory and Hartree-Fock.We find that the mean-field results depend qualitatively and quantitatively on the treatment of exchange-correlation effects,while GW calculations produce results that are in excellent agreement with experimental photoelectron spectra of gas phase ion pairs and ionic liquids.These results establish the GW approach as a valuable tool for understanding the electronic structures of ionic liquids.
