Bright solitons in a spin-orbit-coupled dipolar Bose-Einstein condensate trapped within a double-lattice.

By effectively controlling the dipole-dipole interaction, we investigate the characteristics of the ground state of bright solitons in a spin-orbit coupled dipolar Bose-Einstein condensate. The dipolar atoms are trapped within a double-lattice which consists of a linear and a nonlinear lattice. We derive the motion equations of the different spin components, taking the controlling mechanisms of the dipole-dipole interaction into account. An analytical expression of dipole-dipole interaction is derived. By adjusting the dipole polarization angle, the dipole interaction can be adjusted from attraction to repulsion. On this basis, we study the generation and manipulation of the bright solitons using both the analytical variational method and numerical imaginary time evolution. The stability of the bright solitons is also analyzed and we map out the stability phase diagram. By adjusting the long-range dipole-dipole interaction, one can achieve manipulation of bright solitons in all aspects, including the existence, width, nodes, and stability. Considering the complexity of our system, our results will have enormous potential applications in quantum simulation of complex systems.

Real-imaginary spectrum decomposition of the transparency spectra in microwave dressed Rydberg systems.

To distinguish the contributions of electromagnetically induced transparency (EIT) and Autler-Townes splitting (ATS) in their applications in precision laser spectroscopy, we propose a real-imaginary spectrum decomposition method to investigate the transparency spectra in a four-level microwave (MW) dressed Rydberg system. We show that the opening transparency windows in the absorption spectra of probe field is a prominent character by EIT, EIT-ATS crossover, and ATS when the MW field is turned off and the intensity of the control field is adjusted. When the MW field is turned on and gradually increased, the EIT is destroyed and disappears. In addition, the most prominent characters that open a transparency window are the EIT-ATS crossover and the ATS. Then, if we further increase the intensity of the MW field, we find that the transparency windows open mainly due to the ATS. Compared to the previous considerations of this issue, which were limited to three-level systems, our four-level scheme reported here is useful for understanding the features of quantum interference in multilevel atomic systems, and has potential applications to study enhanced sensitivity, measurement spectroscopic, quantum processing, quantum communication, and transmission.

Observation of carrier transfer in a vertical 0D-CsPbBr3/2D-MoS2 mixed-dimensional van der Waals heterojunction.

Two-dimensional transition metal dichalcogenides with outstanding properties open up a new way to develop optoelectronic devices such as phototransistors and light-emitting diodes. Heterostructure with light-harvesting materials can produce many photogenerated carriers via charge and/or energy transfer. In this paper, the ultrafast dynamics of charge transfer in zero-dimensional CsPbBr3 quantum dot/two-dimensional MoS2 van der Waals heterostructures are investigated through femtosecond time-resolved transient absorption spectroscopy. Hole and electron transfers in the ps and fs magnitude at the interfaces between MoS2 and CsPbBr3 are observed by modulating pump wavelengths of the pump-probe configurations. Our study highlights the opportunities for realizing the exciton devices based on quantum dot/two-dimensional semiconductor heterostructures.

Soliton molecules and their scattering by a localized P T-symmetric potential in atomic gases.

We propose a physical scheme to study the formation of optical soliton molecules (SMs), consisting of two solitons bound together with a π-phase difference, and the scattering of SMs by a localized parity-time (P T)-symmetric potential. In order to stabilize SMs, we apply an additional space-dependent magnetic field to introduce a harmonic trapping potential for the two solitons and balance the repulse interaction induced by the π-phase difference between them. On the other hand, a localized complex optical potential obeying P T symmetry can be created through an incoherent pumping and spatial modulation of the control laser field. We investigate the scattering of optical SMs by the localized P T-symmetric potential, which exhibits evident asymmetric behavior and can be actively controlled by changing the incident velocity of SMs. Moreover, the P T symmetry of the localized potential, together with the interaction between two solitons of the SM, can also have a significant effect on the SM scattering behavior. The results presented here may be useful for understanding the unique properties of SMs and have potential applications in optical information processing and transmission.

Low amplified spontaneous emission threshold from 2-thiophenemethylammonium quasi-2D perovskites via phase engineering.

Quasi-2D Ruddlesden-Popper perovskites attract great attention as an optical gain media in lasing applications due to their excellent optoelectronic properties. Herein, a novel quasi-2D Ruddlesden-Popper perovskite based on 2-thiophenemethylammonium (ThMA) is synthesized by a facile solution-processed method. In addition, an anti-solvent treatment method is proposed to tune the phase distribution, and preferential orientation of quasi-2D (ThMA)2Csn-1PbnBr3n+1 thin films. The large-n-dominated narrow domain distribution improves the energy transfer efficiency from small-n to large-n phases. Also, the highly oriented nanocrystals facilitate the efficient Förster energy transfer, beneficial for the carrier population transfer. Furthermore, a green amplified spontaneous emission with a low threshold of 13.92 µJ/cm2 is obtained and a single-mode vertical-cavity laser with an 0.4 nm linewidth emission is fabricated. These findings provide insights into the design of the domain distribution to realize low-threshold multicolor continuous-wave or electrically driven quasi-2D perovskites laser.

Band evolution and Landau-Zener Bloch oscillations in strained photonic rhombic lattices.

We investigate band evolution of chiral and non-chiral symmetric flatband photonic rhombic lattices by applying a strain along the diagonal direction, and thereby demonstrating Landau-Zener Bloch (LZB) oscillations in the presence of a refractive index gradient. The chiral and non-chiral symmetric rhombic lattices are obtained by adding a detuning to uniform lattices. For the chiral symmetric lattices, the middle flatband is perturbed due to the chiral symmetry breaking while a nearly flatband appears as the bottom band with the increase of strain-induced next-nearest-neighbor hopping. Consequently, LZB oscillations exhibit intriguing characteristics such as asymmetric energy transitions and almost complete suppression of the oscillations. Nevertheless, for the non-chiral symmetric lattices, flatband persists owing to the retained particle-hole symmetry and evolves into the bottom band. Remarkably, the band gap can be readily tuned, which allows controlling of the amplitude of Landau-Zener tunneling (LZT) rate and may lead to thorough LZT. Our analysis provides an alternative perspective on the generation of tunable flatband and may also bring insight to study the symmetry and topological characterization of the flatband.

icMRCI+Q Study of the Spectroscopic Properties of the 14 Λ-S and 49 Ω States of the SiN- Anion in the Gas Phase.

This paper calculates the potential energy curves of the 14 Λ-S and 49 Ω states, which come from the first three dissociation channels of the SiN- anion. These calculations are conducted using the valence internally contracted multireference configuration interaction and the Davidson correction approach. Core-valence correlation and scalar relativistic corrections are taken into account. The potential energies are extrapolated to the complete basis set limit. The spin-orbit coupling is computed using the state interaction approach with the Breit-Pauli Hamiltonian. We found that the X¹Σ⁺ (υ'' = 0-23) and a³Σ⁺ (υ' = 0-2) states of SiN- are stable at the computed adiabatic electron affinity value of 23,262.27 cm-1 for SiN. Based on the calculated potential energy curves, the spectroscopic parameters and vibrational levels were determined for all stable and metastable Λ-S and Ω states. The computed adiabatic electron affinity of SiN and the spectroscopic constants of SiN- (X¹Σ⁺) are all in agreement with the available experimental data. The d³Σ⁺, 25Σ⁺, 15Δ, and 15Σ- quasi-bound states caused by avoided crossings were found. Calculations of the transition dipole moment of a³Σ⁺1 to X¹Σ⁺0+ are shown. Franck-Condon factors, Einstein coefficients, and radiative lifetimes of the transition from the a³Σ⁺1 (υ' = 0-2) to the X¹Σ⁺0+ state are evaluated.

Potential Energy Curves, Transition Dipole Moments, and Franck-Condon Factors of the 12 Low-Lying States of BrO- Anion.

This work investigates the spectroscopic parameters, vibrational levels, and transition probabilities of 12 low-lying states, which are generated from the first dissociation limit, Br(2Pu) + O-(2Pu), of the BrO- anion. The 12 states are X1Σ+, 21Σ+, 11Σ-, 11Π, 21Π, 11Δ, a3Π, 13Σ+, 23Σ+, 13Σ-, 23Π, and 13Δ. The potential energy curves are calculated with the complete active-space self-consistent field method, which is followed by the internally contracted multireference configuration interaction approach with Davidson modification. The dissociation energy D0 of X1Σ+ state is determined to be approximately 26876.44 cm-1, which agrees well with the experimental one of 26494.50 cm-1. Of these 12 states, the 21Σ+, 11Σ-, 21Π, 11Δ, 13Σ+, 23Σ+, 23Π, and 13Δ states are very weakly bound states, whose well depths are only several-hundred cm-1. The a3Π, 23Π, and 13Δ states are inverted and account for the spin-orbit coupling effect. No states are repulsive regardless of whether the spin-orbit coupling effect is included. The spectroscopic parameters and vibrational levels are determined. The transition dipole moments of 12-pair electronic states are calculated. Franck-Condon factors of a number of transitions of more than 20-pair electronic states are evaluated. The electronic transitions are discussed. The spin-orbit coupling effect on the spectroscopic parameters and vibrational properties is profound for all the states except for X1Σ+, a3Π, and 11Π. The spectroscopic parameters and transition probabilities obtained in this paper can provide some powerful guidelines for observing these states in a proper spectroscopy experiment, in particular the states that have very shallow potential wells.

Potential energy curves, spectroscopic parameters, and spin-orbit coupling: a theoretical study on 24 Λ-S and 54 Ω states of C2(+) cation.

The potential energy curves (PECs) of 24 Λ-S states and 54 Ω states of the C2(+) cation are studied in detail using an ab initio quantum chemical method. All the PEC calculations are made for internuclear separations from 0.09 to 1.11 nm by the complete active space self-consistent field method, which is followed by the internally contracted multireference configuration interaction approach with the Davidson modification (MRCI+Q). All the Λ-S states involved dissociate into the first dissociation limit, C((3)Pg) + C(+)((2)Pu), of C2(+) cation, of which only the 2(2)Σg(-) and 2(4)Σg(-) are repulsive. The spin-orbit (SO) coupling effect is accounted for by the Breit-Pauli Hamiltonian with an aug-cc-pCVTZ basis set. To improve the quality of PECs, core-valence correlation and scalar relativistic corrections are included. Core-valence correlation corrections are taken into account with an aug-cc-pCVTZ basis set. Scalar relativistic correction calculations are done by the third-order Douglas-Kroll Hamiltonian approximation with the cc-pVQZ basis set. All the PECs are extrapolated to the complete basis set limit. The convergence observations of present calculations are made, and the convergent behavior is discussed with respect to the basis set and level of theory. With the PECs obtained by the MRCI+Q/CV+DK+56 calculations, the spectroscopic parameters of 22 Λ-S bound states of C2(+) cation are evaluated by fitting the first ten vibrational levels, which are obtained by solving the rovibrational Schrödinger equation using Numerov's method. In addition, the spectroscopic parameters of 51 Ω bound states generated from these Λ-S bound states are also obtained. The spectroscopic parameters are compared with those reported in the literature. Excellent agreement with available measurements is found. It is expected that the spectroscopic parameters of Λ-S and Ω states reported here are reliable predicted ones.

Accurate theoretical study on 18 Λ-S and 50 Ω states of CS in the gas phase: potential energy curves, spectroscopic parameters, and spin-orbit coupling.

The potential energy curves (PECs) of 50 Ω states generated from the 18 Λ-S states are studied for the first time using the complete active space self-consistent field method, which is followed by the internally contracted multireference configuration interaction approach with the Davidson modification. All the 18 Λ-S states correlate to the first dissociation limit, C((3)Pg) + S((3)Pg), of CS molecule, of which only the 2(5)Π is repulsive and the A(1)Π, A(') (1)Σ(+), and 2(3)Σ(+) possess double wells. The spin-orbit (SO) coupling is accounted for by the state interaction approach with the Breit-Pauli Hamiltonian. Core-valence correlation correction is taken into account with an all-electron cc-pCV5Z basis set. Scalar relativistic correction calculations are made by the third-order Douglas-Kroll Hamiltonian approximation at the level of a cc-pVTZ basis set. All the PECs are extrapolated to the complete basis set limit. The a(') (3)Σ(+), e(3)Σ(-), 1(5)Σ(+), 1(5)Π, and d(3)Δ are found to be the inverted Λ-S states with the SO coupling included. The spectroscopic parameters of 17 Λ-S and 41 Ω bound states are evaluated. The comparisons between the present results and available measurements are performed, and excellent agreement has been found. It shows that the spectroscopic results reported here can be expected to be reliable predicted ones.

Investigation of spectroscopic properties and spin-orbit splitting in the XΠ² and AΠ² electronic states of the SO ⁺cation.

The potential energy curves (PECs) of the X(2)Π and A(2)Π electronic states of the SO(+) ion are calculated using the complete active space self-consistent field method, which is followed by the internally contracted multireference configuration interaction (MRCI) approach for internuclear separations from 0.08 to 1.06 nm. The spin-orbit coupling effect on the spectroscopic parameters is included using the Breit-Pauli operator. To improve the quality of PECs and spin-orbit coupling constant (A(0)), core-valence correlation and scalar relativistic corrections are included. To obtain more reliable results, the PECs obtained by the MRCI calculations are corrected for size-extensivity errors by means of the Davidson modification (MRCI+Q). At the MRCI+Q/aug-cc-pV5Z+CV+DK level, the A(0) values of the SO(+)(X(2)Π(1/2, 3/2)) and SO(+)(A(2)Π(1/2, 3/2)) are 362.13 and 58.16 cm(-1) when the aug-cc-pCVTZ basis set is used to calculate the spin-orbit coupling splitting, and the A(0) of the SO(+)(X(2)Π(1/2, 3/2)) and SO(+)(A(2)Π(1/2, 3/2)) are 344.36 and 52.90 cm(-1) when the aug-cc-pVTZ basis set is used to calculate the spin-orbit coupling splitting. The conclusion is drawn that the core-valence correlations correction makes the A(0) slightly larger. The spectroscopic results are obtained and compared with those reported in the literature. Excellent agreement exists between the present results and the measurements. The vibrational manifolds are calculated, and those of the first 30 vibrational states are reported for the J = 0 case. Comparison with the measurements shows that the present vibrational manifolds are both reliable and accurate.

Radiative lifetimes of vibrational levels and transition probabilities of spontaneous emissions of the six lowest-lying triplet states of AlN radical.

The potential energy curves of 23 states of AlN radical are calculated to accurately determine the first several lowest-lying singlet and triplet states. The calculations are done using the CASSCF method, which is followed by the valence internally contracted MRCI approach. The rotationless radiative lifetimes of the vibrational levels are approximately 10-7-10-8 s for the C3Π, D3Π, and E3Δ states, 101-10-4 s for the A3Σ- state, and 10-4-10-5 s for the B3Σ+ state. The origins of the vibronic bands and the radiative lifetimes agree well with the available experimental and other theoretical results. The Einstein coefficients of many vibronic emissions are large for the C3Π-X3Π, C3Π-A3Σ-, D3Π-X3Π, D3Π-A3Σ-, and E3Δ-X3Π transitions and therefore, these transitions are strong. The emissions of the E3Δ-D3Π system are so weak that it is difficult to measure them through spectroscopy. The spectral distribution of the vibronic emissions is evaluated for the transitions of 12 pairs of states. In terms of the radiative lifetimes and transition probabilities obtained here, several spectroscopic routines for observing these states via spectroscopy are proposed.

Spectroscopic parameters, vibrational levels, transition dipole moments and transition probabilities of the 9 low-lying states of the NCl+ cation.

This work calculates the potential energy curves of 9 Λ-S and 28Ω states of the NCl+ cation. The technique employed is the complete active space self-consistent field method, which is followed by the internally contracted multireference configuration interaction approach with the Davidson correction. The Λ-S states are X2Π, 12Σ+, 14Π, 14Σ+, 14Σ-, 24Π, 14Δ, 16Σ+, and 16Π, which are yielded from the first two dissociation channels of NCl+ cation. The Ω states are generated from these Λ-S states. The 14Π, 14Δ, 16Σ+, and 16Π states are inverted with the spin-orbit coupling effect included. The 14Σ+, 16Σ+, and 16Π states are very weakly bound, whose well depths are only several-hundredcm-1. One avoided crossing of PECs occurs between the 12Σ+ and 22Σ+ states. To improve the quality of potential energy curves, core-valence correlation and scalar relativistic corrections are included. The potential energies are extrapolated to the complete basis set limit. The spectroscopic parameters and vibrational levels are calculated. The transition dipole moments are computed. The Franck-Condon factors, Einstein coefficients, and radiative lifetimes of many transitions are determined. The spectroscopic approaches are proposed for observing these states according to the transition probabilities. The spin-orbit coupling effect on the spectroscopic and vibrational properties is evaluated. The spectroscopic parameters, vibrational levels, transition dipole moments, as well as transition probabilities reported in this paper could be considered to be very reliable.

Spectroscopic properties and transition probabilities of SiC+ cation.

This study calculates the potential energy curves of 12 Λ-S and 27â€¯Ω states, which belong to the first dissociation channel of SiC+ cation. The potential energy curves are computed with the complete active space self-consistent field method, which is followed by the valence internally multireference configuration interaction approach with the Davidson correction. The transition dipole moments are determined. Core-valence correlation and scalar relativistic correction, as well as extrapolation of the potential energies to the complete basis set limit are included. The spin-orbit coupling effect on the spectroscopic parameters and vibrational properties is evaluated. The vibrational band origins, Franck-Condon factors, and Einstein coefficients of spontaneous emissions are calculated. The rotationless radiative lifetimes of the vibrational levels are approximately 10-5 s long for the e2Π state. The partial radiative lifetimes of vibrational levels are approximately 10-7 s long for the 24Π and 24Σ- states, 10-5 to 10-6 s long for the 22Σ- state and the first well of the 14Π state, and very short for the second well of the 14Π state. Overall, the emissions are strong for the 22Σ--c2Σ-, 24Σ--X4Σ-, 24Π-X4Σ- transitions, and for the second well of the 14Π-14Σ+ transition. The spectral range of emissions is determined. In terms of the radiative lifetimes and transition probabilities obtained in this paper, some guidelines for detecting these states are proposed via spectroscopy. These results can be used to measure the emissions from the SiC+ cation, in particular, in interstellar clouds.

Accurate spectroscopic calculations of the 22 Λ-S states and 60Ω states of the PS+ cation.

This work studied the potential energy curves of 22 Λ-S states, which were yielded from the first two dissociation limits, P(4Su)+S+(4Su) and P+(3Pg)+S(3Pg), of the PS+ cation. The potential energy curves were calculated employing the CASSCF method, which was followed by the internally contracted MRCI approach with Davidson correction. Core- valence correlation and scalar relativistic corrections as well as basis set extrapolation were included. Of these 22 Λ-S states, only the 35Σ+ state was repluse without the spin-orbit coupling effect, whereas the 35Σ+, 15Δ, 25Σ+, and 15Σ- states were repulse with the spin-orbit coupling effect accounted for. The 21Π and 23Π states had double wells, but the first well of the 23Π state had no vibrational levels and the first well of 21Π state had only one vibrational state. The avoided crossings were found between the 11Π and 21Π states and between the d3Π and 23Π states. The 25Σ+, 15Π, 15Δ, b3Δ, and c3Σ- states were inverted with the spin-orbit coupling effect taken into account. The 15Δ, 25Σ+, 15Σ-, and 21Π states were weakly bound. The spectroscopic properties were evaluated and compared with the experimental and other theoretical results. The Franck-Condon factors of some electronic transitions between different Λ-S states were determined. The vibrational levels of several states were predicted. The spin-orbit coupling effect on the spectroscopic parameters was discussed. Analyses show that the spectroscopic results obtained here can be expected to be reliably predicted ones.

Multireference configuration interaction study of the 27 low-lying states of the PF+ cation.

This paper studied the spectroscopic parameters and vibrational properties of 27 Λ-S and 60Ω states of PF+ cation. The 27 Λ-S states were the X2Π, A2Σ+, B2Π, C2Σ-, D2Δ, a4Σ-, b4Π, c4Σ+, d4Δ, 22Σ+, 32Σ+, 42Σ+, 22Σ-, 32Σ-, 32Π, 42Π, 52Π, 62Π, 22Δ, 32Δ, 12Φ, 24Σ-, 34Σ-, 24Π, 34Π, 16Σ-, and 16Π, which were generated from the first four dissociation limits. The 60Ω states were produced from the 27 Λ-S states. All the potential energy curves were calculated with the CASSCF method, which was followed by the icMRCI+Q approach. The a4Σ-, b4Π, and D2Δ states were inverted with the spin-orbit coupling effect accounted for. The 24Π, 24Σ-, 22Δ, 32Δ, 32Σ+, 42Σ+, 12Φ, and 22Σ- states were repulsive whether the spin-orbit coupling effect was included or not, but the 52Π and D2Δ states became repulsive only with the spin-orbit coupling effect included. The C2Σ- state was very weakly bound. The a4Σ- state had one barrier. The avoided crossings existed between the a4Σ- and 24Σ- states, the 22Σ+ and 32Σ+ states as well as the D2Δ and 22Δ states. Core-valence correlation and scalar relativistic corrections were taken into account. The extrapolation to the complete basis set limit was done. The spectroscopic parameters and vibrational properties were determined. The transition dipole moments were calculated and the Franck-Condon factors of some electric dipole transitions were evaluated. The spin-orbit coupling effect on the spectroscopic and vibrational properties was discussed.

MRCI study of the spectroscopic parameters and transition properties of the 36 low-lying electronic states of the B2 molecule.

This paper studied the spectroscopic and transition properties of 36 low-lying states, which came from the first two dissociation limits of B2 molecule. The potential energy curves were calculated with the complete active space self-consistent field (CASSCF) method, which was followed by the internally contracted multireference configuration interaction (icMRCI) plus Davidson modification (icMRCI+Q) approach. Of these 36 states, the 25Σu-, 15Σu+, 25Πu, and 15Δu states were repulsive; the B3Δu, E3Σu+, f1Σu-, g1Πg, 23Πu, 33Σg-, 33Πu, 15Πg, and 33Σu+ states had double wells; the B3Δu, E3Σu+, G3Σu+, f1Σu-, g1Πg, 33Σg-, 23Πu, 33Πu, 15Πg, 25Πg, 25Σg-, and 33Σu+ states had one barrier; the 25Σg- state and the second wells of B3Δu, E3Σu+, 15Πg, f1Σu-, g1Πg, and 23Πu states were weakly bound; and the 25Σg- state had no vibrational levels. The avoided crossings existed between the B3Δu and 23Δu states, the E3Σu+ and G3Σu+ states, the G3Σu+ and 33Σu+ states, the 33Σu+ and 43Σu+ states, the 23Πu and 33Πu states, the g1Πg and 21Πg states, the 23Σg- and 33Σg- states, the 15Πg and 25Πg states, the 25Πg and 35Πg states, the 25Σg- and 35Σg- states, as well as the F3Πg and 33Πg states. Core-valence correlation and scalar relativistic corrections were taken into account. The extrapolation to the complete basis set limit was done. The spectroscopic parameters and vibrational properties were obtained. The transition dipole moments were calculated. Franck-Condon factors of some transitions were evaluated. The spin-orbit coupling (SOC) effect on the spectroscopic parameters and vibrational properties is tiny and sometimes even can be negligible. The results determined in this paper can provide some powerful guidelines to observe these states, in particular the states which have not been studied in the experiment.

Accurate spectroscopic calculations of the 14Λ-S and 30Ω states of BF+ cation including the spin-orbit coupling effect.

This paper studied the potential energy curves of 30Ω states yielded from the 14Λ-S states (X2Σ+, 12Π, 22Π, 32Π, 12Σ-, 22Σ+, 32Σ+, 12Δ, 14Σ-, 14Σ+, 24Σ+, 14Π, 24Π, and 14Δ) of the BF+ cation. The potential energy curves were calculated for internuclear separations from approximately 0.08 to 1.1nm using the CASSCF method, which was followed by the icMRCI approach with the aug-cc-pV6Z basis set. Of these 14Λ-S states, the 24Σ+ and 24Π states were repulsive. The 22Π and 32Π states had double wells. The avoided crossings were found between the 12Π and the 22Π state, and between the 32Π and the 42Π state. The 12Π, 22Π, 32Π, and 14Π states were inverted with the spin-orbit coupling effect taken into account. The 14Π state and the second wells of 22Π and 32Π states were weakly bound. Each of the 12Π, 22Π, and 32Π states had one barrier. The potential energy curves of all the Λ-S and Ω states were extrapolated to the complete basis set limit. Core-valence correlation and scalar relativistic corrections were included at the level of an aug-cc-pV5Z basis set. The spin-orbit coupling effect was included by the state interaction approach with the Breit-Pauli Hamiltonian and the all-electron cc-pCV5Z set. The spectroscopic parameters were determined and compared with available experimental and other theoretical ones. The spin-orbit coupling effect on the spectroscopic parameters was evaluated in detail. Comparison with available experimental data show that the methodology used in this paper is highly accurate for this system.

Accurate spectroscopic calculations of the 21 Λ-S states and 42 Ω states of the SiB radical.

The potential energy curves were calculated for the 21 Λ-S states, which were generated from the first two dissociation channels, Si(3Pg)+B(2Pu) and Si(1Dg)+B(2Pu), of the SiB radical. The potential energy curves were computed for the 42 Ω states, which arose from the 21 Λ-S states. The calculations were done using the CASSCF method, which was followed by the icMRCI approach. Of these 21 Λ-S states, the D4Σ-, i2Σ+, j2Π, 52Π, and 12Φ states had double wells. The D4Σ-, a2Π, A4Π, e2Π, j2Π, 52Π, h2Δ, and 12Φ states were inverted with the spin-orbit coupling effect taken into account. The 32Δ state and the second wells of D4Σ- and 12Φ states were weakly bound. Core-valence correlation correction, scalar relativistic correction and Davidson correction were included. The spectroscopic parameters were determined and the vibrational properties of some weakly-bound states were predicted. The spin-orbit coupling effect on the spectroscopic parameters was evaluated. Comparison with available experimental data shows that the methodology used is highly accurate for the SiB radical.

Accurate multireference configuration interaction calculations of the 24 Λ-S states and 60 Ω states of the BO(+) cation.

The potential energy curves were calculated for the 24 Λ-S states correlating with the lowest four dissociation channels of the BO(+) cation. The potential energy curves were also computed for the 60 Ω states generated from the 24 Λ-S states. Calculations were made for internuclear separations from 0.08 to 1.05nm using the CASSCF method, which was followed by the icMRCI approach with the correlation-consistent basis sets. Core-valence correlation, scalar relativistic and basis extrapolation were accounted for. Of the 24 Λ-S states, only three states (2(5)Π, 1(5)Σ(-), and 2(5)Σ(-)) were found to be repulsive; only the 1(5)Δ state was found to be a very weakly-bound state; and the E(1)Π, 2(3)Π, and 1(5)Π states were found to be very strong bound. In addition, the B(1)Σ(+) and 3(1)Σ(+) states have double wells by the avoided crossing between the two states. The a(3)Π, 1(3)Σ(-), and 2(3)Σ(-) states are inverted with the spin-orbit coupling effect included. The spectroscopic parameters were determined and the vibrational properties of several Λ-S states were predicted. Comparison with available experimental data shows that the methodology employed is highly accurate for this system.