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Creators/Authors contains: "Kasper, Joseph M."

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  1. ; ; ( , Annual reports in computational chemistry)
    null (Ed.)
    Scientists are extending the computational application of relativistic methods to ever-increasing sizes of molecular systems. To this end, reduction of the computational cost of relativistic methods through modest approximations is a welcome effort. In this work, we review several localized two-component approximations and introduce a maximally localized variant. We also extend the focus of local relativistic approximations from the ground state to excited states. Benchmark calculations on both valence and core electron absorption spectra are carried out to analyze the error incurred by using the relativistic local approximations for excited state computations. 
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    Accepted Manuscript Full Text Available
  2. ; ; ; ( , Chemical Physics Reviews)
    null (Ed.)
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  3. ; ( , Journal of Computational Chemistry)
    Abstract

    While the natural transition orbital (NTO) method has allowed electronic excitations from time‐dependent Hartree‐Fock and density functional theory to be viewed in a traditional orbital picture, the extension to multicomponent molecular orbitals such as those used in relativistic two‐component methods or generalized Hartree‐Fock (GHF) or generalized Kohn‐Sham (GKS) is less straightforward due to mixing of spin‐components and the inherent inclusion of spin‐flip transitions in time‐dependent GHF/GKS. An extension of single‐component NTOs to the two‐component framework is presented, in addition to a brief discussion of the practical aspects of visualizing two‐component complex orbitals. Unlike the single‐component analog, the method explicitly describes the spin and frequently obtains solutions with several significant orbital pairs. The method is presented using calculations on a mercury atom and a CrO2Cl2complex.

     
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  4. ; ; ; ; ; ; ( , Physical Review B)
  5. ; ; ; ( , The Journal of Chemical Physics)
  6. ; ; ( , The Journal of Chemical Physics)
  7. ; ; ; ; ; ( , The Journal of Physical Chemistry C)
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  8. ; ; ( , The Journal of Chemical Physics)
  9. ; ; ; ; ( , The Journal of Chemical Physics)