The conductance of a weakly interacting electron gas in the presense of a single scatterer is found at arbitrary strength of the scattering potential. At weak interaction, a simple renormalization group approach can be used instead of the standard bosonization procedure. Our technique allows to take into account the backscattering of electrons that leads to a non-Luttinger-liquid behavior of the low-temperature conductance. In the presence of magnetic field, the backscattering may give rise to a peak in differential conductance at bias equal to the Zeeman energy.

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We study the low-frequency excitations of a compressible electron liquid confined to a strip and subjected to a magnetic field. Using the classical equations of Inotion, we show the existence of gapless excitations additional to the conventional one-dimensional plasmon. These excitations are shown to have linear spectra. In contrast to the plasmon mode, the velocities of these modes increase with the magnetic Geld in the weak-Geld domain, reaching a maximum at a certain field strength. The calculated oscillator strengths and the estimate for the damping rates enable us to discuss the optimal experimental setup for the observation of the acoustic modes.

Although carbon monoxide (CO) has been known to bind to the ferrous heme in cytochrome P450 enzymes (P450s) since the earliest days of P450 research, details on the nature of the ferrous–CO bonding remain elusive. This study employed dispersion-corrected density functional theory (DFT) calculations and DFT-based theoretical analyses to investigate the complexes between CO and a thiolate- or imidazole-ligated heme that contains ferric or ferrous iron. Traditionally, the ferrous–CO bonding in heme systems has been interpreted qualitatively in terms of σ donation and π backdonation. Complementary occupied-virtual orbital pair (COVP) analysis yielded one orbital pair for σ donation and two for π backdonation together with the specific magnitude of their energetic contributions. The charge-transfer effect for these three orbital pairs has nearly the same energetic significance in the ferrous–CO complexes. Therefore, in total, the π-backdonation effect is much greater than the σ-donation effect. In contrast, the σ-donation effect is more significant in the ferric–CO complex because of the less efficient π backdonation. The nature of ferric–CO and ferrous–CO bonding was further scrutinized using the generalized Kohn–Sham energy decomposition analysis (GKS-EDA) scheme, whose results highlighted the significance of various effects in enhancing the Fe–CO bonding for the thiolate- and imidazole-ligated heme groups. In particular, the intrinsic repulsion effect plays a crucial role in promoting the preferential binding of CO toward the ferrous heme and in determining the geometry of the complexes.

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