Finite-temperature density-functional-theory investigation on the nonequilibrium transient warm-dense-matter state created by laser excitation

Effect of Nonequilibrium Transient Electronic Structures on Lattice Stability in Metals: Density Functional Theory Calculations

“…Thus, this transient state could exist in a time scale longer than the time scale of the pulse and shorter than the time scale of Auger decay. With the excitation of valence electrons in the inner shell, the reduced screening of core electrons [52] results in localization of the valence band. The DOS of electrons in such nonequilibrium transient states is plotted in Figures 1A,B, and we see similar change of the DOS as in [52], which shows small change for Al but considerable localization of valence bands for Cu.…”

“…With the excitation of valence electrons in the inner shell, the reduced screening of core electrons [52] results in localization of the valence band. The DOS of electrons in such nonequilibrium transient states is plotted in Figures 1A,B, and we see similar change of the DOS as in [52], which shows small change for Al but considerable localization of valence bands for Cu. This is mainly due to the semilocal d band in Cu.…”

“…The black curves show the calculated DOS without a hole, the red and blue ones, respectively, represent the DOS with a hole and two holes of every atom in the system. Due to the deeper Coulomb potential which the remaining electrons feel [52], it is clear that these atomlike features shift toward lower energy. The rise of chemical potential is also observed when the excited electrons are increased.…”

“…For example, even the expensive time-depedent density functional theory (TDDFT) calculation cannot include the Auger process. As a small step forward, the variation of occupation number of excited electrons is a good candidate to study the nonequilibrium states within the framework of finite-temperature density functional theory (FTDFT) with less computational cost and has been successfully applied in studying 2D material as well as WDM [51,52].…”

Full Configuration Interaction Excited-State Energies in Large Active Spaces from Subspace Iteration with Repeated Random Sparsification

“…Excited electronic states of molecules and solid-state systems play a crucial role in determining their chemical properties, including their response to irradition by light [1][2][3][4][5][6][7][8] and their behavior at finite temperature. 9,10 But calculating excited-state properties from first principles often proves challenging, particularly for systems of strongly correlated electrons. Rigorous full configuration interaction (FCI) calculations for such systems require the treatment of a number of electronic configurations that scales combinatorially with the number of electrons and the number of orbitals they may occupy, [11][12][13] which has prevented their application to all but the smallest chemical systems.…”