English
norskBlar i forfatter Artikler, rapporter og annet (kjemi) "Kadek, Marius"
Viser treff 1-10 av 10
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Accurate Relativistic Real-Time Time-Dependent Density Functional Theory for Valence and Core Attosecond Transient Absorption Spectroscopy
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-09)First principles theoretical modeling of out-of-equilibrium processes observed in attosecond pump–probe transient absorption spectroscopy (TAS) triggering pure electron dynamics remains a challenging task, especially for heavy elements and/or core excitations containing fingerprints of scalar and spin–orbit relativistic effects. To address this, we formulate a methodology for simulating TAS within ... -
All-electron fully relativistic Kohn-Sham theory for solids based on the Dirac-Coulomb Hamiltonian and Gaussian-type functions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-03)We present the first full-potential method that solves the fully relativistic four-component Dirac-Kohn-Sham equation for materials in the solid state within the framework of atom-centered Gaussian-type orbitals (GTOs). Our GTO-based method treats one-, two-, and three-dimensional periodic systems on an equal footing, and allows for a seamless transition to the methodology commonly used in studies ... -
Anodic Activity of Hydrated and Anhydrous Iron (II) Oxalate in Li-Ion Batteries
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-12)We discuss the applicability of the naturally occurring compound Ferrous Oxalate Dihydrate (FOD) (FeC2O4·2H2O) as an anode material in Li-ion batteries. Using first-principles modeling, we evaluate the electrochemical activity of FOD and demonstrate how its structural water content affects the intercalation reaction and contributes to its performance. We show that both Li0 and Li+ intercalation in ... -
Band structures and Z2 invariants of two-dimensional transition metal dichalcogenide monolayers from fully relativistic Dirac-Kohn-Sham theory using Gaussian-type orbitals
(Journal article; Tidsskriftartikkel, 2023-06-02)Two-dimensional (2D) materials exhibit a wide range of remarkable phenomena, many of which owe their existence to the relativistic spin-orbit coupling (SOC) effects. To understand and predict properties of materials containing heavy elements, such as the transition-metal dichalcogenides (TMDs), relativistic effects must be taken into account in first-principles calculations. We present an all-electron ... -
Cost-Efficient High-Resolution Linear Absorption Spectra Through Extrapolating the Dipole Moment from Real-Time Time-Dependent Electronic-Structure Theory
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023)We present a novel function fitting method for approximating the propagation of the time-dependent electric dipole moment from real-time electronic structure calculations. Real-time calculations of the electronic absorption spectrum require discrete Fourier transforms of the electric dipole moment. The spectral resolution is determined by the total propagation time, i.e. the trajectory length of the ... -
Electrochemical Potential of the Metal Organic Framework MIL-101(Fe) as Cathode Material in Li-Ion Batteries
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-16)We discuss the characteristic factors that determine the electrochemical potentials in a metal-organic framework used as cathode for Li-ion batteries via density functional theory-based simulations. Our focus is on MIL-101(Fe) cathode material. Our study gives insight into the role of local atomic environment and structural deformations in generating electrochemical potential. -
Excitation Energies from Real-Time Propagation of the Four-Component Dirac–Kohn–Sham Equation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-01-21)We report the first implementation of real-time time-dependent density functional theory (RT-TDDFT) at the relativistic four-component level of theory. In contrast to the perturbative linear-response TDDFT approach (LR-TDDFT), the RT-TDDFT approach performs an explicit time propagation of the Dirac–Kohn–Sham density matrix, offering the possibility to simulate molecular spectroscopies involving ... -
Resolution-of-identity accelerated relativistic two- and four-component electron dynamics approach to chiroptical spectroscopies
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-27)We present an implementation and application of electron dynamics based on real-time time-dependent density functional theory (RT-TDDFT) and relativistic 2-component X2C and 4-component Dirac–Coulomb (4c) Hamiltonians to the calculation of electron circular dichroism and optical rotatory dispersion spectra. In addition, the resolution-of-identity approximation for the Coulomb term (RI-J) is introduced ... -
ReSpect: Relativistic spectroscopy DFT program package
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-11)With the increasing interest in compounds containing heavier elements, the experimental and theoretical community requires computationally efficient approaches capable of simultaneous non-perturbative treatment of relativistic, spin-polarization, and electron correlation effects. The ReSpect program has been designed with this goal in mind and developed to perform relativistic density functional ... -
X-ray absorption resonances near L2,3-edges from real-time propagation of the Dirac–Kohn–Sham density matrix
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-07)The solution of the Liouville–von Neumann equation in the relativistic Dirac–Kohn–Sham density matrix formalism is presented and used to calculate X-ray absorption cross sections. Both dynamical relaxation effects and spin–orbit corrections are included, as demonstrated by calculations of the X-ray absorption of SF6 near the sulfur L2,3-edges. We also propose an analysis facilitating the interpretation ...
