Ab initio MRCI+Q study on potential energy curves and spectroscopic parameters of low-lying electronic states of CS^+

Carbon monosulfide molecular ion （CS＋）, which plays an important role in various research fields, has long been attracting much interest. Because of the unstable and transient nature of CS＋, its electronic states have not been well investigated. In this paper, the electronic states of CS＋ are studied by employing the internally contracted multireference configuration interaction method, and taking into account relativistic effects （scalar plus spin–orbit coupling）. The spin–orbit coupling effects are considered via the state-interacting method with the full Breit–Pauli Hamiltonian. The potential energy curves of 18 Λ–S states correlated with the two lowest dissociation limits of CS＋ molecular ion are calculated, and those of 10 lowest Ω states generated from the 6 lowest Λ–S states are also worked out. The spectroscopic constants of the bound states are evaluated, and they are in good agreement with available experimental results and theoretical values. With the aid of analysis of Λ–S composition of Ω states at different bond lengths, the avoided crossing phenomena in the electronic states of CS＋ are illuminated. Finally, the single ionization spectra of CS （X1Σ＋） populating the CS＋（X2Σ1/2＋, A2Π3/2, A2Π1/2, and B2Σ1/2＋） states are simulated. The vertical ionization potentials for X2Σ1/2＋, A2Π3/2, A2Π1/2, and B2Σ1/2＋ states are calculated to be 11.257, 12.787, 12.827, and 15.860 eV, respectively, which are accurate compared with previous experimental results, within an error margin of 0.08 eV^0.2 eV.

Different Charging-Induced Modulations of Highest Occupied Molecular Orbital Energies in Fullerenes in Comparison with Carbon Nanotubes and Graphene Sheets

The highest occupied molecular orbital（HOMO） energies of fullerenes are found by quantitative first-principles calculations to be raised by negative charging, and the rising rate rank of the fullerenes is C60 >C70 >C80 >C90>C100 >C180. Then we compare fullerenes with carbon nanotubes（CNTs） and graphene sheets（GSs） and find that the increase of the HOMO energy of a fullerene is much faster than that of CNTs and graphene sheets with the same number of C atoms. The rising rate rank is fullerene>CNT>GS, which holds no matter what the number of C atoms is or which structure the fullerene isomer is. This work paves a new path for developing all-carbon devices with low-dimensional carbon nanomaterials as different functional elements.

Extending the Standard Model in Hyper-Dimensional Mechanics

According to studies on the precursive time quantum variable, this publication presents an in-depth analysis of the chapter on the correlation between the nuclear mass and electroweak force. This research shows that there is a close correlation between the nuclear mass and the energy of the orbitals which underlies the electroweak interaction.

Quantitative structure-activity relationships for joint toxicity of substituted phenols and anilines to Scenedesmus obliquus

There are often many chemicals coexisting in aquatic ecosystems, and few information on the joint toxicity of a mixture of organic pollutants is available at present. The 48-h toxicity of substituted phenols and anilines and their binary mixtures to Scenedesmus obliquus was determined by the algae inhibition test. The median effective inhibition concentration EC50 values for single compounds and EC50mix values for coexistent compounds were obtained. The n-octanol/water partition coefficient （logPmlx） and the frontier orbital energy gap （AEmlx） for mixtures were calculated. The following two-descriptor quantitative structure-activity relationships （QSARs） models were developed to predict single toxicity and joint toxicity respectively： log（1/ECs0） = 0.445logP - 0.801AE ＋ 9.501 （r2 = 0.876） and log （1/EC50mix） = 0.338logPmix- 0.492AEmix ＋ 6.928 （r^2 = 0.831）. The two equations were found to fit well. In addition, the model derived from the structural parameters of single components in binary mixtures log（1/EC50mix） = 0.2221ogP - 0.277AE ＋ 5.250 （r^2 = 0.879） can be used successfully to predict the toxicity of a mixture.

Prediction of Toxicity of Phenols and Anilines to Algae by Quantitative Structure-activity Relationship

Objective To measure the toxicity of phenol, aniline, and their derivatives to algae and to assess, model, and predict the toxicity using quantitative structure-activity relationship （QSAR） method. Methods Oxygen production was used as the response endpoint for assessing the toxic effects of chemicals on algal photosynthesis. The energy of the lowest unoccupied molecular orbital （ELUMO） and the energy of the highest occupied molecular orbital （EHOMO） were obtained from the ChemOffice 2004 program using the quantum chemical method MOPAC, and the frontier orbital energy gap （△E） was obtained. Results The compounds exhibited a reasonably wide range of algal toxicity. The most toxic compound was α-naphthol, whereas the least toxic one was aniline. A two-descriptor model was derived from the algal toxicity and structural parameters： logl/EC50=0.2681ogKow-1.006△E＋11.769 （n=20, r^2=0.946）. This model was stable and satisfactory for predicting toxicity. Conclusion Phenol, aniline, and their derivatives are polar narcotics. Their toxicity is greater than estimated by hydrophobicity only, and addition of the frontier orbital energy gap AE can significantly improve the prediction of logKow-dependent models.

Quantitative structure-activity relationships for the Toxicity of Substituted Benzenes to Cyprinus carpio

To measure the 96h-LC50 values of 32 substituted benzenes to the carp and to study the relationship between quantitative structure-activity and structural parameters of chemicals. Methods The acute toxicity values of 32 substituted benzenes to the carp were determined in a semistatic test. The energy of the lowest unoccupied molecular orbital, and the highest occupied molecular orbital, the dipole moment and the molecular weight of substituted benzenes were calculated by the quantum chemical method MOPAC6.0. Results The range of the toxicity of studied compounds was broad, and the most toxic compound was pentachlorophenol, while the least toxic compound was 4-methylaniline. By the stepwise regression analyses, a series of Quantitative structure-activity relationships (QSAR) equations were derived from all compounds and subclasses. The equation log1/LC50=0.759logP +2.222 (R2 (adj)=0.818) was found to fit well and the average predicted percentage error was 6.16%. Conclusion The toxicity of anilines and phenols to the carp could be modeled well by logP alone, whereas the toxicity of the halogenated benzenes and nitrobenznes not containing hydroxyl or amino group can be controlled by hydrophobic and electronic factors.

Principle for the Working of the Lithium-Ion Battery

The technological advances in Lithium-ion batteries have created many new applications, including electric vehicles. In this short note, we shall explain in simple terms the basic physics why and how it is possible to have high energy capacity in Lithium-ion batteries. However, heating has been a common problem and without appropriate design, they might give fire and explosion as reported.

ADSORPTION MECHANISM OF SOME BIVALENT HEAVY METAL CATIONS IN SOLUTIONS USING MONTMORILLONITE

The frontier orbital energies of montmorillonite molecule and[Me(H_(2)O)_(6)]^(2+)(Me=Cu^(2+),Zn^(2+),Co^(2+)and Ni^(2+))were calculated by INDO method.Results showed that the chemical interaction between montmorillonite molecule and[Cu(H_(2)O)_(6)]^(2+)or[Zn(H_(2)O)_(6)]^(2+)was possible.The experimental results of powder X-ray diffraction and isothermal adsorption supported the above-mentioned calculation results.

MRCI+Q study of the low-lying electronic states of CdF including spin-orbit coupling

Cd F molecule, which plays an important role in a great variety of research fields, has long been subject to numerous researchers. Due to the unstable nature and heavy atom Cd containing in the Cd F molecule, electronic states of the molecule have not been well studied. In this paper, high accurate ab initio calculations on the Cd F molecule have been performed at the multi-reference configuration interaction level including Davidson correction（MRCI ＋ Q）. Adiabatic potential energy curves（PECs） of the 14 low-lying Λ–S states correlating with the two lowest dissociation limits Cd（~1S_g） ＋ F（~2P_u） and Cd（~3P_u） ＋ F（~2P_u） have been constructed. For the bound Λ–S and ？ states, the dominant electronic configurations and spectroscopic constants are obtained,and the calculated spectroscopic constants of bound states are consistent with previous experimental results. The dipole moments（DMs） of 2 Σ＋ and 2Π are determined, and the spin–orbit（SO） matrix elements between each pair of X2Σ＋, 22Σ＋, 12Π, and 22Π are obtained. The results indicate that the sudden changes of DMs and SO matrix elements arise from the variation of the electronic configurations around the avoided crossing region. Moreover,the Franck–Condon factors（FCFs）, the transition dipole moments（TDMs）, and radiative lifetimes of low-lying states-the ground state X2Σ＋are determined. Finally, the transitional properties of 22Π–X2Σ＋and 22Σ＋–X2Σ＋are studied. Based on our computed spectroscopic information of Cd F, the feasibility and challenge for laser cooling of Cd F molecule are discussed.

La_(0.67)Sr_(0.33)MnO_(3)薄膜相图的轨道弹性调控

过渡金属氧化物具有丰富的功能性,但其错综复杂的内部自由度对相图绘制和结构设计提出了挑战.本文中,我们引入了描述相图物理起源的轨道能级序(ELO),并通过对La_(0.67)Sr_(0.33)MnO_(3)(LSMO)氧化物的研究证明了其在相图预测中的有效性.结合DFT计算和实验,我们构建了氧含量和应变关联的LSMO相图,结果表明LSMO结构稳定性与ELO密切相关.据此发现了一种由ELO演化而产生的四倍氧有序相.最后,我们提出了描述轨道分裂程度的轨道弹性定律,阐明了ELO演化的起源,助力功能氧化物的设计.这项研究拓宽了材料科学领域的性能调控手段,并为从轨道角度预测相图提供了思路.

Dynamics of non-metal-regulated FeCo bimetal microenvironment on oxygen reduction reaction activity and intrinsic mechanism

The change in the coordination environment of the active sites of a fuel cell cathode catalyst provides a new modulation strategy for stimulating the catalyst’s oxygen reduction reaction activity.The thermodynamic and electronic properties of the FeCoN5A and FeCoN6A catalyst structures with nonmetallic A-doped(A=B,N,O,P,and S)coordination were calculated and analyzed based on density functional theory.The modulation order of G*OH by different A-doped FeCo bimetal pairs(BMPs)was as follows:S>P>O>N/C>B.There was a dynamic distribution of charges in the coordination environment during the adsorption of OH,which resulted in inversely proportional relationship with the charge transfer between the adsorbate OH,active site,first coordination layer,and second coordination layer in turn.Descriptors of the orbital energy levels of neighboring nonmetal atoms were constructed based on the p-electron number and electronegativity of the doped nonmetal A.The change of the orbital energy levels of the first coordination atom during the adsorption process caused the structure to exhibit different adsorption energies.This study provides new insights on the non-metallic modulation of the M-N-C coordination environment to improve the oxygen reduction reaction activity.

Quantum-chemical study on the catalytic activity of Ti_nRu_mO_2(110)surfaces on chlorine evolution

Based on the generalized gradient approximation （GGA）, Perdew-Wang-91 （PW91） combined with a periodic slab model has been applied to study the catalytic activity of chlorine evolution on TinRumO2 （1 1 0） surface. Metal oxide model TinRumO2 has been established with pure TiO2 and Ru02 on the basis set of Double Numerical plus polarization （DNP）, in which the proportion of n：m was 3：1, 1 ：l, or 1：3. Analysis on the reaction activity in the electrochemical reaction and the electrochemical desorption reaction was based on Frontier molecular orbital theory. The results show that the TinRumO2 with a ratio of Ti：Ru at 3：1 is best facilitates the electrochemical reaction and electrochemical desorption reaction to produce M-Clads intermediate and precipitate C12. In addition, the adsorption energy of Cl on the surface of Ti3RU102 possesses the minimum value of 2.514 eV, and thus electrochemical desorption reaction could occur most easily.