Energy core excitation

Further energy transfer within the rods may be performed by the /3f-chromophores of the PBS rods, modulated by the various 30 kDa-linker polypeptides, and directed along the central rod channel towards the APC complexes of the PBS core. Excitation energy transfer in the PBS was found to occur in up to five steps with different energy transfer rates [134] within the discs (hexamers) from (s)- to (f)-chromophores and from (f)- to (f)-chromophores, from disc to disc, from the rods to the APC complexes in the core, to the APB-Lcm complex and to Chi a in the PS II complex. The disc-to-disc excitation energy transfer (20 ps) was supposed to be the rate-limiting step. 

Abstract This chapter discusses descriptions of core-ionized and core-excited states by density functional theory (DFT) and by time-dependent density functional theory (TDDFT). The core orbitals are analyzed by evaluating core-excitation energies computed by DFT and TDDFT their orbital energies are found to contain significantly larger self-interaction errors in comparison with those of valence orbitals. The analysis justifies the inclusion of Hartree-Fock exchange (HFx), capable of reducing self-interactions, and motivates construction of hybrid functional with appropriate HFx portions for core and valence orbitals. The determination of the HFx portions based on a first-principle approach is also explored and numerically assessed. 

Description of core orbitals is investigated by estimating core-excitation energies of carbon monoxide, computed by the self-interaction corrected (SIC)-ASCF and SIC-TDDFT methods. First, the formulations of SIC-ASCF and SIC-TDDFT are briefly introduced, and subsequently numerical analysis is demonstrated. 

In time-dependent Hartree-Fock (TDHF) and TDDFT calculations, the selfinteractions for unoccupied orbitals are automatically corrected. Here, in order to remove the SIEs of occupied orbitals, the following modified A matrix is adopted to estimate SIC core-excitation energies ... 

The combination of Eq. (14.8) with Eq. (14.13) leads to SIC core-excitation energies. In this study, all Perdew-Zunger SIEs are estimated in a post-SCF manner. 

Table 14.2 summarizes CO core-excitation energies calculated by the ASCF and SIC-ASCF methods using HF and KS-DFT with BLYP, B3LYP, and BHHLYP. 

As is widely known, KS-DFT succeeds in reproducing standard enthalpies of formation of the small G2 set within 3-7 kcal/mol with commonly used functionals [71], Since the ASCF method estimates excitation energies from total energies of two different states, the accuracy for the core-excitation energies is predictable. 

The core orbitals in the third-row elements have been also examined by estimating core-excitation energies [52], The numerical assessment demonstrates that 70 and 50 % portions of HFx are appropriate for K-shell and L-shell electrons, which requires to modify CV-B3LYP so as to deal with three different HFx portions, 20, 50, and 70 % for valence, L-shell, and K-shell electrons. The following is the extension of CV-B3LYP. 

Table 14.13 Is and 2p core-excitation energies of SiH4, PH3, H2S, HCl, and CI2 molecules by TDDFT with the modified CV-B3LYP functional with cc-pCVTZ plus Rydberg basis functions in eV...

Takahashi O, Pettersson LG (2004) Functional dependence of core-excitation energies. J Chem Phys 121 10339-10345... 

Ground state properties 168 3.3.1. 3d core excitation energies 196... 

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