Magnus W. D. Hanson-Heine
A scaled CIS(D) based method for the calculation of valence and core electron ionization energies
Hanson-Heine, Magnus W. D.; George, Michael W.; Besley, Nicholas A.
Michael W. George
Nicholas A. Besley
The calculation of electron ionisation energies is a key component for the simulation of photoelectron spectroscopy. CIS(D) is a perturbative doubles correction for the single excitation conﬁguration interaction (CIS) method which provides a new approach for computing excitation energies. It is shown that by introducing a virtual orbital subspace that consistsofasingle’ghost’orbital,valenceelectronionisationenergiescanbecomputedusingascaledCIS(D)approach with an accuracy comparable with considerably more computationally intensive methods, such as ionisation-potential equationofmotioncoupledclustertheory(EOM-IP-CCSD),andsimulatedspectrashowasigniﬁcantimprovementrelative to spectra based upon Koopmans’ theorem. When the model is applied to the ionisation energies for core orbitals thereis anincrease intheerror, particularlyfor theheavier nucleiconsidered (siliconto chlorine), althoughthe relative energy of the ionisation energies are predicted accurately. In addition to its inherent computational efﬁciency relative to other wavefunction based approaches, a signiﬁcant advantage of this approach is that the ionisation energies for all electrons can be obtained in a single calculation, in contrast to∆self-consistent ﬁeld based methods.
|Journal Article Type||Article|
|Publication Date||Jul 21, 2019|
|Journal||The Journal of Chemical Physics|
|Peer Reviewed||Peer Reviewed|
|APA6 Citation||Hanson-Heine, M. W. D., George, M. W., & Besley, N. A. (2019). A scaled CIS(D) based method for the calculation of valence and core electron ionization energies. Journal of Chemical Physics, 151(3), doi:10.1063/1.5100098|
|Keywords||Physical and Theoretical Chemistry; General Physics and Astronomy|
|Additional Information||This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in J. Chem. Phys. 151, 034104 (2019) and may be found at (https://doi.org/10.1063/1.5100098|
Nick Besley A Scaled CIS(D) Based Method