On the basis of precisely treating various physical effects-including core-valence electron correlation, scalar relativistic, spin-orbit coupling, and extrapolation to the complete basis set limit, this study constructs the potential energy curves of 18 Lambda-S states and the corresponding 35 Omega states of the SH+ ion by means of the optimized icMRCI+Q method. Within the all-electron icMRCI/cc-pCV5Z+SOC theoretical framework, the transition dipole moment curves of 12 pairs of transitions between 7 Omega states[including X-3 Sigma(-)(0+), X-3 Sigma(-)(1), (1)2(1st well)(upsilon' = 0-8), (2)0(+)(upsilon' = 0-5), (2)2(1st well)(upsilon' = 0-2), (2)1(1st well)(upsilon' = 0-2), and (3)0(+)(upsilon' = 0-2)] are calculated. Based on the aforementioned potential energy curves and transition dipole moment curves, the spectral data of each state and the transition data between Omega states are determined by solving the Schr & ouml;dinger equation for nuclear motion and combining with the corresponding formulas, and the obtained results are in excellent agreement with the experimental values. In addition, the spectral characteristics of the 12 pairs of radiative transitions are clarified, the variation laws of the radiative lifetimes(tau(upsilon'J')) and radiation widths(Gamma(r)) of the excited Omega states are revealed, and the influence of the rotational quantum number(J') on the radiative lifetimes(tau(upsilon'J')) of the (2)2(1st well)(upsilon' = 0-2, +), (2)1(1st well)(upsilon' = 0-2, +), and (3)0(+)(upsilon' = 0-2, +) states is discussed. The datasets presented in this paper, including the potential energy curves of 18 Lambda-S and 35 Omega states, 12 pairs of transition dipole moments between the 7 Omega states[X-3 Sigma(-)(0+), X-3 Sigma(-)(1), (1)2(1st well)(upsilon' = 0-8), (2)0(+)(upsilon' = 0-5), (2)2(1st well)(upsilon' = 0-2), (2)1(1st well)(upsilon' = 0-2), and (3)0(+)(upsilon' = 0-2)], and variation of the radiative lifetimes(tau(upsilon'J')) with J' for the (2)2( 1st well)(upsilon' = 0-2, +), (2)1(1st well)(upsilon' = 0-2, +), and (3)0(+)(upsilon' = 0-2, +) states of SH+ ion, are openly available at https://www.doi.org/10.57760/sciencedb.j00213.00233.

A global potential energy surface (PES) for the CH 2 (1 1 A′) was constructed using neural network method based on high‐level ab initio points. The topographic features of the PES were discussed and compared with available theoretical and experimental values. The results indicate that the present PES is accurate and reliable. To further clarify the reality of the PES, the dynamics calculations of the C( 1 D) + H 2 → H + CH(X 2 Π) reaction were performed using time‐dependent wave packet method. Some meaningful dynamic results including reaction probability, integral cross section, differential cross section, and rate constant were calculated and compared with previous theoretical and experimental values. The reasonable dynamics results indicate that the present PES can be used to perform any kind of dynamics studies.

Global diabatic potential energy surfaces (PESs) of the PH2+ associated with 13A″ and 23A″ states were constructed by using a neural network method combined with a symmetry-adapted function. In the construction of PESs, high-level ab initio points were calculated by the multireference configuration interaction method in conjunction with the aug-cc-pVQZ basis set for H and the aug-cc-pwCVQZ basis set for P. The topographical features of the diabatic PESs were discussed and compared with the ab initio results, confirming that the diabatic PESs were successfully constructed. To further validate the reliability of the diabatic PESs, adiabatic and nonadiabatic dynamics calculations of the P+(3P) + D2 reaction were performed using a time-dependent wave packet method. The integral cross sections were reported and compared with experimental data. The results indicate that the nonadiabatic values are, in general, in good agreement with experimental data, while the adiabatic dynamics results tend to overestimate the actual values.

Based on the selection of appropriate active space and basis sets, and consideration of various physical effects such as scalar relativistic effect, core-valence electron correlation, complete basis set limit and spin-orbit coupling effect, the precise ionization energy of X-3 Sigma(-)/a(1)Delta/b(1)Sigma(+)/A(3)H/c(1)H(OH+)<-(XH)-H-2(OH), and the potential energy curves of 14 Lambda-S and 27 Q states of OH+ are obtained by using the optimized icMRCI + Q method. The transition dipole moments between six Q states[X-3 Sigma(-)(0) ,X-3 Sigma(- )(1) , (1)2, (2)2, (2)1, and (1)0-] are obtained by X-3 Sigma(-)(0)+ ,X-3 Sigma(-)(1) using the all electron icMRCI/cc-pCV5Z + SOC theory. The ionization energy, spectroscopic and vibrational- rotational transition data obtained in this work are in good agreement with the existing measurements. The findings in this work are as follows. 1) The radiation lifetimes of (1)2(v' = 0-6, J' = 2, +) gradually decrease with v' increasing, while the radiation widths correspondingly increase; the spontaneous emissions of (1)2(v' = 0-6, J' = 2, +)- (v", J" = 1, -) are weak. 2) The radiation lifetimes of (2)21st well (v ' = 0-2, J' = 2, +), ,X-3 Sigma(-)(1) (2)1(v' = 0-9, J' = 1, +), and (1)0-(v' = 0-8, J' = 0, +) all gradually increase as v' increases, while their radiation widths narrow with v' increasing; the spontaneous emissions of (2)21st well (v ' = 0-2, J' = 2, +)- (v", J" = 1, -), (2)1(v' = 0-9, J' = 1, +)- X-3 Sigma(- )(0+),X-3 Sigma(-)(1) - (v", J" = 1, -), and (1)0-(v' = 0-8, J' = 0, +)- X-3 Sigma(-)(0) 1 (v", J" = 1, -) are strong. 3) The radiation lifetimes of (2)21st well (v ' = 0-2, +), (2)1(v' = 0-9, +), and (1)0-(v' = 0-8, +) all gradually increase with J' increasing. The datasets presented in this work, including the potential energy curves of 14 Lambda-S and 27 Q states, 7 pairs of transition dipole moments between the 6 Omega states [ X-3 Sigma(-)(0)+ ,X-3 Sigma(-)(1), (1)2, (2)2, (2)1, (1)0-], and distributions of the radiative lifetime varying with the J' of the (2)2( 1st well )(v ' = 1 0-2, +), (2)1(v' = 0-9, +), and (1)0-(v' = 0-8, +) states

On the basis of correcting various errors caused by spin-orbit coupling effects, scalar relativity effects, core-valence correlation effects and basis set truncation, the potential energy curves of 10 Λ-S states and 26 Ω states of AlH molecule are calculated by using icMRCI + Q method. The transition dipole moments of 6 pairs of transitions between the \begin{document}${\rm X}{}^1\Sigma _{{0^ + }}^ + $\end{document}, \begin{document}$ {\rm a^3}{\Pi _{{0^ + }}} $\end{document}, \begin{document}${\rm a^3}{\Pi _1} $\end{document}, \begin{document}${\rm a^3}{\Pi _2} $\end{document}, and \begin{document}${\rm A^1}{\Pi _1} $\end{document} states are calculated by using the icMRCI/AV6Z* theory with the consideration of spin-orbit coupling effects. The spectral and transition data obtained here for AlH molecule are in very good agreement with the available experimental measurements. The findings are below. 1) The transition intensities are relatively strong of the Q(J″) branches for the (0, 0), (0, 1), (0, 2), (1, 0), (1, 1), (1, 2), (1, 3), (1, 4) and (1, 5) bands of the A1Π1 – \begin{document}${\rm X}{}^1\Sigma _{{0^ + }}^ + $\end{document} transition, with the increase of J″; the Einstein A coefficients and vibrational branching ratio gradually decrease, and the weighted absorption oscillator strength gradually increases of Δυ = 0 band, the Einstein A coefficient, vibrational branching ratio, and weighted absorption oscillator strength gradually increase for the Δυ ≠ 0 bands. 2) The radiation lifetimes of A1Π1(υ' = 0, 1) increases slowly as the J' increases. 3) The A1Π1(υ' = 0 and 1, J' = 1, +) →\begin{document}${\rm X}{}^1\Sigma _{{0^ + }}^ + $\end{document}(υ'' = 0–3, J'′ = 1, –) transition of AlH molecule satisfies the criteria for laser cooling of diatomic molecules, that is, the vibrational branching ratio of the highly diagonal distribution, the extremely short radiation lifetimes of the A1Π1(υ' = 0 and 1, J' = 1, +) states, and the intermediate electronic states \begin{document}$ {\rm a^3}{\Pi _{{0^ + }}} $\end{document}, a3Π1, and a3Π2 do not interfere with laser cooling. Therefore, based on the cyclic transition A1Π1(υ' = 0 and 1, J' = 1, +) ↔ \begin{document}${\rm X}{}^1\Sigma _{{0^ + }}^ + $\end{document}(υ'′ = 0–3, J'' = 1, –), we propose a feasible scheme for laser cooling of AlH molecule. When cooled, 2.541 × 104 photons can be scattered by four pump lasers used in the visible range, which are enough to cool AlH to the ultra-cold temperature, and the Doppler temperature and recoil temperature of the main transition are on the order of μK.

In this work, the potential energy curves of eight low electronic states (X1Σ+, a3Π, A1Π, b3Σ-, 23Π, 13Σ+, 15Σ-, and 15Π) and twenty-three Ω states of BH molecule, and the transition dipole moments among the \begin{document}$ {\text{X}}{}^{\text{1}}{\Sigma}_{{{\text{0}}^ + }}^ + $\end{document}, \begin{document}$ {{\text{a}}^{\text{3}}}{\Pi_{{{\text{0}}^ + }}} $\end{document}, a3Π1, a3Π2, and A1Π1 states are calculated by using the internally contracted multireference configuration interaction (icMRCI) method. In order to obtain the accurate potential energy curve, the errors caused by single and double electron excitation, core-valence correlation effects, relativistic effects and basis set truncation are corrected. The spectral and transition data of BH molecule are in good agreement with the available theoretical and experimental data. The calculation results show that the A1Π1(υ′ = 0-2, J′ = 1, +) →\begin{document}$ {\text{X}}{}^{\text{1}}{\Sigma}_{{{\text{0}}^ + }}^ + $\end{document}(υ′′ = 0-2, J′′ = 1, –) transition has large Einstein A-coefficient, weighted absorption oscillator strength, and highly diagonal vibrational branching ratio Rυ′υ′′, and the excited state A1Π1(υ′ = 0, 1) have short spontaneous radiation lifetimes. Moreover, the effects of \begin{document}$ {{\text{a}}^{\text{3}}}{\Pi_{{{\text{0}}^ + }}} $\end{document}and a3Π1 states on A1Π1(υ′ = 0) ↔ \begin{document}$ {\text{X}}{}^{\text{1}}{\Sigma}_{{{\text{0}}^ + }}^ + $\end{document}(υ′′ = 0) cycle transition can be ignored. Therefore, according to the A1Π1(υ′ = 0-1, J′ = 1, +) ↔ \begin{document}$ {\text{X}}{}^{\text{1}}{\Sigma}_{{{\text{0}}^ + }}^ + $\end{document}(υ′′ = 0-3, J′′ = 1, –) cycle transition, we propose to apply one main cooling laser (λ00 = 432.45 nm) and two repumping lasers (λ10 = 479.67 nm and λ21 = 481.40 nm) to laser cooling BH molecules, and evaluation of the cooling effect.

The potential energy curves for four Λ-S and eight Ω states of the AlD molecule are calculated by using the valence internally contracted multireference configuration interaction approach with the Davidson modification (icMRCI+Q). The core-valence correlation and relativistic corrections are included. The extrapolation of potential energies to the complete basis set limit is made. Transition dipole moments (TDMs) between the six bound Ω states are also calculated by the icMRCI approach. The calculated spectroscopic constants are in good agreement with the available experimental data and theoretical values. Based on the obtained potential energy curves and transition dipole moments, highly diagonal Franck-Condon factors and vibrational branching ratios are determined for the A1π1(υ'=0,1)→X1Σ+0+(υ'') transition, short spontaneous radiative lifetime and narrow radiative width for the excited state A1π1 (υ'=0, 1) are also predicted. On this account, the optical scheme of the laser cooling for AlD molecule is constructed with A1π1(υ')↔X1Σ+0+(υ'') as the close-loop transition. The proposed laser drives X1Σ+0+(υ'')→A1π1(υ') transition by using three wavelengths (main laser beam λ00=420.96 nm; two repumping laser beams λ10=443.00 nm and λ21=448.94 nm). The Doppler temperature (TDoppler=44.94 μK) and recoiltemperature(TRecoil=3.73 μK) for the A1π1 (υ'=0)X1Σ+0+ (υ''=0) transition are also calculated. These results can provide theoretical support for the experimental study of laser-cooled AlD molecules.

ABSTRACT Sulfur monoxide radical has widely been detected in outer space using ground-state spectroscopy. The a 1Δ2 and b 1Σ+0+ states of this radical have low excitation energies, and they possibly exist in outer space. In this work, the potential energy curves and dipole moment functions of the two states were evaluated using the complete active space self- consistent field method, followed by the valence internally contracted multireference configuration interaction approach. The transition line positions, oscillator strengths, band transition dipole matrix elements, Einstein A coefficients, and Franck–Condon factors of all transitions were calculated for lower vibrational levels at rotational angular momentum quantum number J up to 150. The transition line positions calculated in this study are in good agreement with the experimental results. The rovibrational transition became noticeably weak at Δυ > 5. Comparing the results of a 1Δ2 and b 1Σ+0+ states reported in this paper with the previous values, we conclude that these results are the most accurate and complete to date. GRAPHICAL ABSTRACT

In this study, we calculated the properties of the transition between six lowest-lying triplet states (X-3 Sigma(-)(g), A'(3)Delta(u), A(3)Sigma(+)(u), B ''(3)Pi(u), B-3 Sigma(-)(u), and B'(3)Pi(g)) of sulphur dimer. The calculations were made with the CASSCF method, followed by the valence icMRCI approach. It was found that the radiative lifetime of the B-3 Sigma(-)(u) state is in the order of 10 ns. The Einstein A coefficients of certain vibronic emissions from the B-3 Sigma(-)(u) - X-3 Sigma(-)(g) system were large, and the radiative lifetimes of the B'Pi(g) and B ''Pi(u) states were found to be in the order of 1 and 10 mu s, respectively. The B'(3)Pi(g) - A'(3)Delta(u), B'(3)Pi(g) - A(3)Sigma(+)(u), and B ''(3)Pi(u) - X-3 Sigma(-)(g) transitions were strong and could be measured by spectroscopy. In contrast, the B'(3)Pi(g) - B ''(3)Pi(u) and B'(3)Pi(g) - B-3 Sigma(-)(u) transitions were weak and therefore, difficult to be detected via spectroscopy. The distributions of the radiative lifetimes with varying rotational angular momentum quantum number were evaluated for some lower vibrational states of the B ''(3)Pi(u), B-3 Sigma(-)(u) , and B'(3)Pi(g) states. The spin-orbit coupling effect on the transition properties of the B ''Pi(u) - X-3 Sigma(-)(g)( )system was also studied. The radiative lifetimes of the B ''(3)Pi(u, 0+), B ''(3)Pi(u, 1), and B ''(3)Pi(u, 2) states were in the order of 10(-6) - 10(-7), 10(-6) - 10(-7), and 10(-5) s, respectively. The transition properties reported in this study can be used to guide the detection of sulphur dimers in both laboratory experiments and astrophysical environments. (C) 2019 Elsevier Ltd. All rights reserved.

Carbon monosulfide was detected in outer space by rovibrational spectroscopy of the X 1Σ+ state and A 1Π – X 1Σ+ system. This work calculated the potential energy curves and dipole moment functions of the X 1Σ+0+ and A 1Π1 states, and computed the transition dipole moments between the two states employing the CASSCF method, followed by the valence icMRCI approach. Core-valence correlation and scalar relativistic corrections were included. The extrapolation of potential energies to the complete basis set limit was performed. The spin-orbit coupling effect was included. The Einstein A coefficients, band origins, and oscillator strengths were calculated for the rovibrational transitions when J ≤ 150. The rovibrational transitions of the X 1Σ+0+ and A 1Π1 states became very weak when Δυ ≥ 6. The Einstein A coefficients of vibronic emissions of the A 1Π1 – X 1Σ+0+ system were large, indicating that the emissions were able to be measured easily through spectroscopy. Several rovibrational transitions of the A 1Π1 – X 1Σ+0+ system were analysed in detail. The distribution of radiative lifetime varying as rotational quantum number was calculated. The results obtained in this work agree well with the available experimental values.

Carbon monosulfide was detected in outer space by rovibrational spectroscopy of the X (1)sigma(+) state and A (1)pi - X (1)sigma(+) system. This work calculated the potential energy curves and dipole moment functions of the X (1)sigma(+)(0+) and A (1)pi(1) states, and computed the transition dipole moments between the two states employing the CASSCF method, followed by the valence icMRCI approach. Core-valence correlation and scalar relativistic corrections were included. The extrapolation of potential energies to the complete basis set limit was performed. The spin-orbit coupling effect was included. The Einstein A coefficients, band origins, and oscillator strengths were calculated for the rovibrational transitions when J <= 150. The rovibrational transitions of the X (1)sigma(+)(0+) and A (1)pi(1) states became very weak when Delta upsilon >= 6. The Einstein A coefficients of vibronic emissions of the A (1)pi(1) - X (1)sigma(+)(0+) system were large, indicating that the emissions were able to be measured easily through spectroscopy. Several rovibrational transitions of the A (1)pi(1) - X (1)sigma(+)(0+) system were analysed in detail. The distribution of radiative lifetime varying as rotational quantum number was calculated. The results obtained in this work agree well with the available experimental values.

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.

In this study, we calculated the potential energy curves of the X-3 Pi, A(3)Sigma(-), B-3 Sigma(+), C-3 Pi, D-3 Delta, and E-3 Pi states of SiC molecules and the transition probabilities between them. The rotationless radiative lifetimes of the vibrational levels are in the order of 10(-5) s for the A(3)Sigma(-) state, 10(-5)-10(-6) s for the B-3 Sigma(+) state, and 10(-6) to 10(-7) s for the C-3 Pi and E-3 Pi states. This suggests that the spontaneous emissions originating from these states can easily occur. The rotationless radiative lifetimes vary in the range of 10(-3)-10(-5) s for the vibrational levels of the D-3 Delta state. The lifetime of the D-3 Delta, state rapidly decreases with the increasing vibrational level, indicating that the occurrence of spontaneous emissions originating from this state at lower levels is more inhibited than those at higher levels. The emissions of the A(3)Sigma(-)-X-3 Pi, B-3 Sigma(+)-X-3 Pi, C-3 Pi-X-3 Pi, C-3 Pi-A(3)Sigma(-), D-3 Delta-X-3 Pi, and E-3 Pi-X-3 Pi system are strong, suggesting that these transitions can be measured easily by spectroscopy. The emissions of the D-3 Delta-C-3 Pi and E-3 Pi-D-3 Delta systems are weak, suggesting that these transitions are difficult to detect by spectroscopy. The spectral range of the strong emissions from the A(3)Sigma(-)-X-3 Pi system is in the infrared region. The strong emissions of the B-3 Sigma(+)-X-3 Pi, C-3 Pi-X-3 Pi, and C-3 Pi-A(3)Sigma(-) systems are of visible light. Some of these strong emissions, especially those from the A(3)Sigma(-)-X-3 Pi system, could be expected to be detectable in carbon star IRC + 10,126 and the circumstellar shell. (C) 2019 Elsevier Ltd. All rights reserved.

Sulfur monoxide radical has widely been detected in outer space using ground-state spectroscopy. The a 1Δ2 and b 1Σ+0+ states of this radical have low excitation energies, and they possibly exist in outer space. In this work, the potential energy curves and dipole moment functions of the two states were evaluated using the complete active space self- consistent field method, followed by the valence internally contracted multireference configuration interaction approach. The transition line positions, oscillator strengths, band transition dipole matrix elements, Einstein A coefficients, and Franck–Condon factors of all transitions were calculated for lower vibrational levels at rotational angular momentum quantum number J up to 150. The transition line positions calculated in this study are in good agreement with the experimental results. The rovibrational transition became noticeably weak at Δυ > 5. Comparing the results of a 1Δ2 and b 1Σ+0+ states reported in this paper with the previous values, we conclude that these results are the most accurate and complete to date.

In this study, the potential energy curves are calculated for the a(1)Sigma(+), b(1)Pi, c(1)Delta, d(1)Sigma(+), e(1)Pi, f(1)Delta, and g(1)Sigma-states of the AlN radical. The transition dipole moments between them are computed. The rotationless radiative lifetimes of the vibrational levels are found to be approximately several mu s for the d(1)Sigma(+) and g(1)Sigma-states, on the order of several hundred ns for the e(1)Pi state, and one-tenth to several mu s for the deep well of the f(1)Delta state. These results suggest that the spontaneous emissions originated from these states occur readily. The rotationless radiative lifetimes of the vibrational levels are on the order of 10-100 mu s for the c(1)Delta state, 1000 mu s for the vdW minimum of the f(1)Delta state, and 10-1000 mu s for the b(1)Pi state. In addition, the rotationless radiative lifetimes of these states decrease with the increasing vibrational level. This result suggests that the spontaneous emissions generated from these states at lower levels should be difficult to occur. The Einstein coefficients of spontaneous emissions from the d(1)Sigma(+)-a1 Sigma(+), d(1)Sigma(+)-b(1)Pi, e(1)Pi-a1 Sigma(+), e(1)Pi-b(1)Pi, and g(1)Sigma-b(1)Pi systems, as well as from the f(1)Delta state to the b(1)Pi and c(1)Delta states are large, indicating that the emissions of these systems can be measured readily via spectroscopy. The Einstein coefficients of the e(1)Pi-d(1)Sigma(+) transition are very small and the emissions originating from the vdW minimum of the f(1)Delta state are very weak, predicting that these transitions are very difficult to be detected in spectroscopy experiments. (C) 2018 Elsevier Ltd. All rights reserved.

This paper models the variation of emissivity with temperature or/and surface oxidation. The emissivity measurements were done at a wavelength of 1.5 mu m over the temperature range from 800 to 910 K. The sample was heated to a certain temperature in air and kept at that temperature for approximately 6 h during the experiment. The radiation was received by an InGaAs detector. The surface temperature of samples was measured by two thermocouples, which were symmetrically welded on the surface of the samples. The average of their readings was regarded as the true temperature. Eleven models were used to investigate the variation of emissivity with growth of an oxide layer on the sample surface at a certain temperature. The effect of the number of parameters used in the models on the fitting quality was evaluated. The fitting quality of the emissivity models with the same number of parameters was compared. The variation of emissivity with temperature was studied at a certain thickness of the oxide film. Three approximate models were used to explore the variation in emissivity with temperature and thickness of the oxide layer, with two of them being found to accurately reproduce the emissivity. The strong oscillations of emissivity were observed during the initial heating period, which were affirmed to arise from the interference effect between the two radiations stemming from the oxide film and coming from the substrate.

This work studied the variation in spectral emissivity with growth of oxide layer at the different temperatures. For this reason, we measured the normal spectral emissivity during the growth of oxide layer on the sample surface at a wavelength of 1.5 mu m over a temperature range 800-1100 K. In the experiment, the temperature was measured by the two thermocouples, which were symmetrically welded onto the front surface of specimens. The average of their readings was regarded as the true temperature. The detector should be perpendicular to the specimen surface as accurately as possible. The variation in spectral emissivity with growth of oxide layer was evaluated at a certain temperature. Altogether 11 emissivity models were evaluated. The conclusion was gained that the more the number of parameters used in the models was, the better the fitting accuracy became. On the whole, all the PEE models, the four-parameter LEE model and the five-parameter PFE, PLE and LEE models could be employed to well fit this kind of variation. The variation in spectral emissivity with temperature was determined at a certain thickness of oxide film. Almost all the models studied in this paper could be used to accurately evaluate this variation. The approximate models of spectral emissivity as a function of temperature and oxide-layer thickness were proposed. The strong oscillations of spectral emissivity were observed, which were affirmed to arise from the interference effect between the two radiations stemming from the oxide layer and from the substrate. The uncertainties in the temperature of steel 430 generated only by the surface oxidization were approximately 4.1-10.7 K in this experiment. (C) 2017 Elsevier B.V. All rights reserved.

In this paper, we calculate the potential energy curves of 5 Lambda-S and 10 Omega, which arise from the first two dissociation limits of the AIH(+) cation. The calculations are done using the complete active space self-consistent field method, which combines with the valence internally contracted multireference configuration interaction plus the Davidson modification (icMRCI+Q) approach with the aug-cc-pV6Z basis set. To improve the reliability and accuracy of the potential energy curves, the core-valence correlation and scalar relativistic correction, as well as the extrapolation of potential energy to the complete basis set limit are taken into account. The spin-orbit coupling is computed using the state interaction approach with the Breit-Pauli Hamiltonian. Employing the potential energy curves obtained in this study, we evaluate the spectroscopic parameters and vibrational levels for the bound and quasi-bound 4 Lambda-S and 8 Omega states. The computed spectroscopic constants of X-2 Sigma+ and A(2)Pi states are all in agreement with the available experimental data. Moreover, the present theoretical energy separations between each higher channel (Al+(P-3(0)) + H(S-2(1/2)), Al+(P-3(1)) + H(S-2(1/2)), and Al+(P-3(2)) + H(S-2(1/2)) and the lowest one (Al+(S-1(0)) + H(S-2(1/2))) are in excellent agreement with the experimental values. The transition dipole moments are calculated using the valence internally contracted multireference configuration interaction approach with the aug-cc-pV6Z basis set for the 2(1/2) -> X-2 Sigma(+)(1/2) and A(2)Pi(3/2) -> X-2 Sigma(+)(1/2). Based on the obtained potential energy curves and transition dipole moments, highly diagonally distributed Franck-Condon factors (f(00) and f(11)) and large vibrational branching ratios are determined for the 2(1/2)(1st well) (v'=0, 1) -> X2 Sigma 1/2+ (v ") and A(2)Pi(3/2)(v'=0,1)-> X-2 Sigma(1/2)+(v) transitions; short spontaneous radiative lifetime and narrow radiative width for the 2(1/2)1st well (v'=0, 1) and A(2)Pi(3/2) (v'=0, 1) are also predicted in this study, which are suitable for the rapid laser cooling of the AlH+ cation. The three required laser cooling wavelengths are all in the ultraviolet region, that is, 1) for the X-2 Sigma(1/2)+(v ") -> 2(1/2)(1st well) (v') transition:the main repumping laser lambda 00=358.74 nm, two repumping lasers lambda 10=379.27 nm and lambda(21)=374.86 nm; 2) for the X-2 Sigma(+)(1/2) (v ") -> A(2)Pi(3/2) (v') transition:the main repumping laser lambda(00)=357.43 nm, two repumping lasers lambda(10)=377.80 nm and lambda(21)=373.26 nm. In addition, the recoil temperature for the X-2 Sigma(+)(1/2) (v "=0)-> 2(1/2)1st well (v'=0) and X-2 Sigma(1/2)+ (v "=0)-> A(2)Pi(3/2) (v'=0) transitions are obtained. The results imply the feasibility of laser cooling of AlH+ cation. In addition, the spin-orbit coupling effect on the spectroscopic parameter, vibrational level, and laser cooling of AlH+ cation are evaluated.

In this paper, we study the spectroscopic properties and predissociation mechanisms of 14 states, which come from the first two dissociation channels of the BF+ cation. The potential energy curves of 14 Λ-S (X2Σ+, 12Π, 22Π, 22Σ+, 14Σ+, 14Δ, 14Σ1, 12Δ, 12Σ1, 32Σ+, 14Π, 24Π, 24Σ+, and 32Π) and corresponding 30 Ω states are calculated using the complete active space self-consistent field method, which is followed by the valence internally contracted multireference configuration interaction approach with the Davidson modification. To improve the reliability and accuracy of the potential energy curves, the core-valence correlation and scalar relativistic corrections, as well as the extrapolation of potential energy to the complete basis set limit are taken into account. The spin-orbit coupling is computed using the state interaction approach with the Breit-Pauli Hamiltonian. Based on these potential energy curves, the spectroscopic parameters and vibrational levels are determined for all the bound and quasi-bound Λ-S and Ω states. The present ground-state spectroscopic constants match well with the available experimental data. In addition, the vertical and adiabatic ionization potentials from the X1Σ+ state of BF molecule to the X2Σ+, 12Π, and 22Σ+ states of BF+ cation are calculated. The results of BF+(X2Σ+) ← BF(X1Σ+) ionization are in good agreement with the measurements. Various curve crossings of Λ-S states are revealed. We calculate the spin-orbit matrix elements between two interacting electronic states in the curve crossing region. With the help of present spin-orbit coupling matrix elements, we analyze the predissociation mechanisms of X2Σ+ and 32Π states along with the perturbations of the nearby states to 22Π, 14Σ+ and 32Σ+ states for the first time. The predissociation of X2Σ+ and 32Π states have a chance to occur around the vibrational levels υ"=30 and υ'=0 due to spin-orbit coupling, respectively. The present results also indicate that the υ' ≥ 9 vibrational levels of 22Π state are perturbed by the crossing states 22Σ+, 14Σ+, 14Δ, 14Σ1, 12Δ, 12Σ1, 32Σ+, and 14Π, that the υ' ≥ 4 vibrational levels of 14Σ+ state are perturbed via the interacting states 14Σ1 and 12Σ1, and the great perturbations between υ' ≥ 4 vibrational levels of 32Σ+ state and υ' ≥ 0 vibrational levels of 14Π state. For the 30 Ω state, we also calculate the relative energies of dissociation limits compared with the lowest one matching well with the experimental ones. Finally, the Franck-Condon factors, Einstein coefficients, and radiative lifetimes are evaluated for the 22Π (υ'=0-9)-X2Σ+, 22Σ+ (υ'=0-2)-X2Σ+, (3)1/2-(1)1/21st well, and (2)3/2 (υ'=0-9)-(1)1/21st well transitions.

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.