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Abstract: The density functional method PW91P86 with relativistic effective core potentials (RECP) and LANL2DZ basis set have been used to investigate the possible stable geometrical configurations and relative stabilities of the lowest-lying isomers of iridium-doped gold clusters, Au n Ir (n =1–8). Several low-lying isomers were determined. The results indicate that the ground-state Au n Ir, n =1–8, clusters have planar structures except for n =7. The stability trend of the Au n Ir clusters shows that even-numbered Au n Ir clusters are relatively more stable than the neighbouring odd-numbered ones, and indicating the Au2Ir clusters are magic cluster with high chemical stability. [ABSTRACT FROM AUTHOR]

Abstract: The density functional method PW91P86 with relativistic effective core potentials (RECPs) and LANL2DZ basis set has been used to investigate the possible stable geometrical configurations and relative stabilities of the lowest-lying isomers of rhodium-doped gold clusters, Au n Rh (n=1–8). Several low-lying isomers were determined. The results indicate that the ground-state Au n Rh, n=1–8, clusters have planar structures except for n=5 and 8. The stability trend of the Au n Rh clusters shows that the clusters with even numbers of atoms are more stable than the clusters with odd numbers of atoms, indicating that the Au5Rh cluster is a magic cluster with high chemical stability. [Copyright &y& Elsevier]

Abstract: Nickel-doped gold cluster anions, Au n Ni− (n =1–5), were investigated using the density functional method B3LYP with relativistic effective core potentials (RECP) and LANL2DZ basis set. The possible stable geometrical configurations with their electronic states are determined, and many of them in electronic configurations with a high spin multiplicity. The stability trend of the anionic clusters is compared to that of neutral clusters. Our results show that the one excess electron is strong enough to modify the known growth pattern and stability trend of the neutral Au n Ni clusters, and indicate that the stability and electron affinity of the clusters alter with odd-even oscillations as a function of the number of gold atoms. [Copyright &y& Elsevier]

The structural, electronic, and spectral properties of Al n Cu k (n = 1–16; k = 0, ±1) clusters have been examined via ab initio calculations combined with the CALYPSO method. It is found that the Cu atom in the ground-state Al n Cu k cluster is situated on the surface for n = 1–11 and prefers a central site for n = 12–16 (except for in Al 15 Cu, Al 12 Cu+, and Al 16 Cu+). The stability, chemical activity, ionization potential, and electron affinity of the Al n Cu k clusters are closely linked to the cluster size, the number of valence electrons, the point group, and the spin state. Simultaneously, we simulated UV spectra, photoelectron spectra, and vibrational and Raman spectra of the Al n Cu k clusters. The global minimum structure of the A l n Cu− cluster is recognized by our comparing the simulated and measured photoelectron spectra. The spectra and orbital of Al 13 Cu alloy cluster. [Display omitted] • The dopant Cu atom in big aluminum clusters tends to occupy the most highly coordinated location. • The closed-shell structures are able to significantly enhance the stability of the Al n Cuk clusters. • The symmetry of Cu-doped aluminum cluster has a large influence on its chemical activity. • The major dissociation products of Al n Cu + cluster is Al+(or Al) and Al n-1 Cu (or Al n-1 Cu+). [ABSTRACT FROM AUTHOR]

Abstract: Ab initio method based on density-functional theory has been used to investigate the Au n Pd− (n=1–5) cluster anions. The possible stable geometrical configurations with their electronic states are determined, and the energy gaps between the HOMO and LUMO of the ground states are investigated. Our results show that the one excess electron is strong enough to modify the known growth pattern of the neutral Au n Pd clusters, and indicate that the larger is the Au n Pd cluster, the smaller are the distortions by the one excess electron. [Copyright &y& Elsevier]

[Display omitted] • Self-acidification was mainly attributed to sulfur disproportionation. • Supplying alkalinity to bulk was essential to control self-acidification. • S0FB achieved 7–129 times higher of TN removal rate than S0PB. • S0FB achieved 26–65 times higher of TP removal rate than S0PB. The sulfur fluidizing bioreactor (S0FB) has significant superiorities in treating nitrate-rich wastewater. However, substantial self-acidification has been observed in engineering applications, resulting in frequent start-up failures. In this study, self-acidification was reproduced in a lab-scale S0FB. It was demonstrated that self-acidification was mainly induced by sulfur disproportionation process, accounting for 93.4 % of proton generation. Supplying sufficient alkalinity to both the influent (3000 mg/L) and the bulk (2000 mg/L) of S0FB was essential for achieving a successful start-up. Furthermore, the S0FB reached 10.3 kg-N/m3/d of nitrogen removal rate and 0.13 kg-PO 4 3-/m3/d of phosphate removal rate, respectively, surpassing those of the documented sulfur packing bioreactors by 7–129 times and 26–65 times. This study offers a feasible and practical method to avoid self-acidification during restart of S0FB and highlights the considerable potential of S0FB in the treatment of nitrate-rich wastewater. [ABSTRACT FROM AUTHOR]