[en] Highlights: • 24 Λ–S states are correlated to the dissociation limit of Si(³P_g) + Si⁺(²P_u) are first reported. • The dissociation energies of the calculated electronic states are predicted in our work. • It is first time that the entire 54 Ω states generated from the 24 Λ–S states have been studied. • PECs of Λ–S and Ω states are depicted with the aid of avoided crossing rule between the same symmetry. - Abstract: Ab initio all-electron relativistic calculations of the low-lying excited states of Si₂⁺ have been performed at MRCI+Q/AVQZ level. The calculated electronic states, including 12 doublet and 12 quartet Λ–S states, are correlated to the dissociation limit of Si(³P_g) + Si⁺(²P_u). Spin–orbit interaction is taken into account via the state interaction approach with the full Breit-Pauli Hamiltonian, which causes the entire 24 Λ–S states to split into 54 Ω states. This is the first time that spin–orbit coupling (SOC) calculation has been performed on Si₂⁺. The obtained potential energy curves (PECs) of Λ–S and Ω states are respectively depicted with the aid of the avoided crossing rule between the same symmetry. The spectroscopic constants of the bound Λ–S and Ω states are determined, and excellent agreements with the latest theoretical results are achieved

[en] Quasi-classical trajectory calculations have been carried out for the reaction H+HS by using the newest triplet ³A^potential energy surface (PES). The effects of the collision energy and reagent initial rotational excitation are studied. The cross sections and thermal rate constants for the title reaction are calculated. The results indicate that the integral cross sections (ICSs) are sensitive to the collision energy and almost independent to the initial rotational states. The ro-vibrational distributions for the product H2 at different collision energies are presented. The investigations on the vector correlations are also performed. It is found that the collision energies play a postive role on the forward scatter of the product molecules. There is a negative influence on both the alignment and orientation of the product angular momentum for low collision energy at low energy region. Whereas the influence of collision energy is not obvious at high energy region

[en] Highlights: • Total 28 Λ-S states of the NTe molecule have been calculated for the first time. • The polarity of the ground state for NTe is determined to be N^δ−Te^δ+. • The SOC effects make the lowest 10 Λ-S states split into 30 Ω states. • The Ω-state transitions borrow TDMs from the spin-allowed Λ-S transitions via SOC. - Abstract: The entire 28 Λ-S electronic states correlated to four dissociation limits of the NTe molecule have been reliably characterized for the first time. The potential energy curves (PECs) and wavefunctions of these Λ-S states are calculated using the multi-reference configuration interaction plus Davidson correction (MRCI+Q) approach, with all-electron correlation-consistent basis sets at quadruple-zeta level. The spectroscopic constants of the bound Λ-S states are determined from the PECs, and the excellent agreement with previous work is derived. By analyzing the dipole moment, the polarity of the ground state for NTe is determined to be N^δ−Te^δ+, which is contrary to the case of NO. The spin-orbit coupling (SOC) effect is included when the state interaction method is applied. The SOC effect is found to be substantial for the NTe molecule, which makes the lowest 10 Λ-S states split into 30 Ω states. The X²Π states split into two Ω states including X²Π_1/2(X₁1/2) and X²Π_3/2(X₂3/2), and the corresponding SOC splitting is computed to be 1975 cm⁻¹(0.245 eV). Analysis of Λ-S compositions for the Ω-state wavefunction indicates the strong interaction among the Λ-S states. Additionally, the transition properties of the Ω-state transitions 1/2(2)-X₁1/2, 1/2(4)-X₁1/2, 3/2(10)-X₂3/2, and 5/2(1)-X₂3/2 were predicted. These transitions are all mainly from the spin-forbidden Λ-S transitions, but their transition dipole moments arise from those of the spin-allowed Λ-S transitions via the SOC effect. Accordingly, these transitions have quite long radiative lifetimes that are at the microsecond (ms) level.

[en] We have reported the reaction probability, integral reaction cross section, and rate constant for the title system calculated with the aid of a time-dependent wave packet approach. The ab initio potential energy surface (PES) of Prudente et al. (Chem. Phys. Lett. 2009, 474, 18) is employed for the purpose. The calculations are carried out over the collision energy range of 0.05-1.4 eV for the two reaction channels of H + LiH → Li + H₂ and H_b + LiH_a → LiH_b + H_a. The Coriolis coupling (CC) effect are taken into account. The importance of including the Coriolis coupling quantum scattering calculations are revealed by the comparison between the Coriolis coupling and the centrifugal sudden (CS) approximation calculations

[en] The quantum reactive scattering dynamics calculations are carried out over the collision energy range of 0-1.0 eV on the double many-body expansion (DMBE) potential energy surface reported by Poveda and Varandas [Phys. Chem. Chem. Phys. 7 (2005) 2867]. The reaction probabilities, integral cross-section and rate constants for the title reaction are calculated. The calculated rate constants are in agreement with the available experimental results at high temperature but lower than the experimental results at low temperature. (authors)

[en] A time-dependent quantum wave packet method is used to investigate the dynamics of the Li+ H(D)Cl reaction based on a new potential energy surface (J. Chem. Phys. 146 164305 (2017)). The reaction probabilities of the Coriolis coupled (CC) and centrifugal sudden (CS) calculations, the integral cross sections, the reaction rate constants are obtained. The rate constants of the Li+ HCl reaction are within the error bounds at low temperature. A comparison of the CC and CS results reveals that the Coriolis coupling plays an important role in the Li+ H(D)Cl reaction. The CC cross sections are larger than the CS results within the entire energy range, demonstrating that the Coriolis coupling effect can more effectively promote the Li+ DCl reaction than the Li+ HCl reaction. It is found that the isotope effect has a great influence on the title reaction. (paper)

[en] The entire 12 Λ–S states of CCl⁺ correlated to ground state atom C⁺ and Cl are calculated at scalar relativistic MRCI+Q/AV5Z level of theory. Spin–orbit interaction causes the 12 Λ–S states to split into 23 Ω states. The potential energy curves (PECs) of Λ–S and Ω states are depicted with the aid of the avoided crossing rule between the same symmetry. This is the first time that spin–orbit coupling (SOC) calculation has been carried out on CCl⁺. The spin–orbit coupling effect, leading to many avoided crossings, is found to be substantial for CCl⁺. The spectroscopic constants of the bound Λ–S and Ω states are determined, where a better agreement with experimental data is found. The predissociations for a³Π and A¹Π induced by SOC are analyzed. Moreover, the transition properties, including transition dipole moments and Franck–Condon factors, are derived. Subsequently, the radiative lifetimes of transition a³Π₀₊–X¹Σ⁺₀₊ and a³Π₁–X¹Σ⁺₀₊ are calculated. -- Highlights: ► Spectroscopic constants for the ¹Δ, ¹Σ⁻, ¹Σ⁺(II), ³Σ⁺(I), ³Δ, ³Σ⁻, ³Π(II) and ¹Π(II) are firstly reported. ► The dissociation energies of the calculated electronic states are predicted in our work. ► It is first time that the entire 23 Ω states generated from the 12 Λ–S states have been studied. ► The predissociations for a³Πand A¹Π induced by SOC are firstly analyzed for CCl⁺. ► The transition properties including the TDMs, FC factors and radiative lifetimes are evaluated

[en] Highlights: • . The proton transfer of SA is demonstrated by steady and transient configuration. • . Substituent induces smaller Stokes shift by hindering the decrease in aromaticity. • . Two main decay pathways of SA are proposed with their fluorescent dynamics. -- Abstract: The fluorescent behaviors and nonadiabatic dynamics of salicylideneanilines and its two derivatives have been theoretical studied. The enol form transfers to cis-keto after photoexcitation to the first single (S₁) excited state without any energy barrier, and the derivatives with substituent of chlorine and hydroxyl have similar dynamics progress. The excited state intramolecular proton transfer occurs in 46 fs by the results of nonadiabatic dynamics together with photoexcitation progress, which is also demonstrated by the results of geometric structure and infrared spectra. The potential curves scan indicates the energy difference before and after the proton transfer reaction of Enol (11.12 kcal/mol) is larger than that of Enol-CL (8.97 kcal/mol), and the Stokes shift of Enol (257 nm) is larger than that of Enol-CL (200 nm) and Enol-OH (198 nm). This comparison confirms the substitute of chlorine and hydroxyl hinder the decrease in aromaticity after photoexcitation and energy difference between the ground (S₀) and the S₁ state, thereafter induce smaller Stokes shift. The energy barrier between Enol and Cis-keto (5.96 kcal/mol) and energy difference between Cis-keto and Trans-keto (10.27 kcal/mol) are so small that there is a decay pathway of Enol (S₀)→proton transferred Cis-keto (S₁)→fluorescent Cis-keto (S₀)→Enol (S₀) or Cis-keto (S₁) → Trans-keto (S₁)→fluorescence of Trans-keto (S₀)→Enol (S₀).