Correlation effects in the electronic structure of the Ni-based superconducting KNi2S2

The LDA plus Gutzwiller variational method is used to investigate the groundstate physical properties of the newly discovered superconducting KNi2S2. Five Ni-3d Wannier-orbital basis are constructed by the density-functional theory, to combine with local Coulomb interaction to describe the normal state electronic structure of Ni-based superconductor. The band structure and the mass enhanced are studied based on a multiorbital Hubbard model by using Gutzwiller approximation method. Our results indicate that the correlation effects lead to the mass enhancement of KNi2S2. Different from the band structure calculated from the LDA results, there are three energy bands across the Fermi level along the X-Z line due to the existence of the correlation effects, which induces a very complicated Fermi surface along the X-Z line. We have also investigated the variation of the quasi-particle weight factor with the hole or electron doping and found that the mass enhancement character has been maintained with the doping.Comment: 12 pages, 6 figure

The Error Control Methods of Information System in Sensor Networks

Information System Error Discovery took a lot of interests of information system experts. Indeed, this concept has been interpreted in more than one way. This paper describes the connections between 1) the Field-to-Scope Proportion and the Identifying and Managing way of Error Discovery and 2) the (Transmission, Influence and Implementing) TII model and Error Scope. The main goal of the work described here, is to seek deeper understanding of Error Discovery in general and, at last, to find easier ways of confirming it. Second, in this paper we try to model the TII evaluating using Work Expressing System which is Relational Graph. We also use this process model to present the relationship between Error Discovery, TII, (Field-To-Scope Proportion) FSP and Error Scope. After explaining the relationship between Semantic Error and Error Discovery, we improve the Relational Graph model by adding standard. We then offer instructions of the Relational Graph

Vibronic fine structure in the nitrogen 1s photoelectron spectra from Franck-Condon simulations II: Indoles

The vibronic coupling effect in nitrogen 1s X-ray photoelectron spectra (XPS) was systematically studied for a family of 17 bicyclic indole molecules by combining Franck-Condon simulations (including the Duschinsky rotation effect) and density functional theory. The simulated vibrationally-resolved spectra of 4 molecules agree well with available experiments. Reliable predictions for this family further allowed us to summarize rules for spectral evolution in response to three types of common structural changes (side chain substitution, CH$\leftrightarrow$N replacement, and isomerization). Interestingly, vibronic properties of amine and imine nitrogen are clearly separated: they show negative and positive $\Delta$ZPE (zero-point vibration energy of the core-ionized with respect to the ground state), respectively, indicating flatter and steeper PESs induced by the N 1s ionization; amine N's show stronger mode mixing effects than imine N's; the 1s ionizations on two types of nitrogens led to distinct changes in local bond lengths and angles. The rules are useful for a basic understanding of vibronic coupling in this family, and the precise spectra are useful for future reference and data mining studies

Vibrationally-resolved X-ray spectra of diatomic systems: Time-independent and time-dependent simulations

We systematically investigated vibronic coupling effects in X-ray spectra of diatomic systems using time-independent (TI) and time-dependent (TD) methods. Under the TI framework, we studied 5 systems (N$_2$, N$_2^+$, NO$^+$, CO, CO$^+$) in their lowest C/N/O 1s excited or ionized states, generating 10 X-ray absorption (XAS) or photoelectron (XPS) spectra using density functional theory (DFT) with two pure (BLYP, BP86) and two hybrid (B3LYP, M06-2X) functionals. Excellent agreement between theoretical and experimental spectra was found in most systems, except that in O1s XAS of CO and NO$^+$, intensities of higher-energy peaks were underestimated. We established a connection between their complex vibronic structures and the significant geometrical changes induced by the O1s hole. Functional dependence in diatomic systems is generally more pronounced than in polyatomic ones. In all examined cases, pure functionals exhibit better or similar spectral accuracy to hybrid functionals, attributed to superior prediction accuracy in bond lengths and vibrational frequencies. With the TD wavepacket method, we simulated vibrationally-resolved XAS of CO$^+$, NO$^+$, and CO using potential energy curves (PECs) generated at both DFT and multiconfigurational levels. Both TD and TI generate similar C/O 1s XAS spectra of CO$^+$. For O1s XAS of NO$^+$ and CO, TD calculations significantly improved the corresponding TI results, demonstrating sensitivity to the anharmonic effect and the PEC quality. TI and TD approaches are complementary, with practical applications depending on the ease and accuracy of excited-state geometry optimization or PEC scanning, and the significance of anharmonicity. DFT with pure functionals is recommended for diatomic calculations due to its easy execution and reliable accuracy. TI is optimal for most scenarios, but TD is needed for problems with strong anharmonic effects.Comment: 11 figure

Euphorbia factor L8: a diterpenoid from the seeds of Euphorbia lathyris

The title compound [systematic name: (2S*,3S*,4R*,5R*,9S*,11S*,15R*)-5,15-diacet­oxy-3-nicotino­yloxy-14-oxolathyra-6(17),12(E)-diene], C30H37NO7, was isolated from the seeds of Euphorbia lathyris. The tricyclic diterpenoid molecule contains an 11-membered ring, a five-membered ring exhibiting an envelope conformation and a three-membered ring. The 11-membered ring is cis-fused with the three-membered ring and trans-fused with the five-membered ring