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The potential energy curves (PECs) of nine low-lying electronic states (X2Σ+, A2Π, B2Σ+, C2Δ, D2Π, a4Σ+, 14Δ, b4Π and 14Σ−) of the CO+ cation have been studied using an ab initio quantum chemical method. The calculations have been performed employing the complete active space self-consistent field (CASSCF) method followed by the valence internally...
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... to those reported in theoretical work [28,34], here we have also found that two potential wells exist on the PEC of the D 2 P electronic state. One well is around 0.12591 nm, and the other is around 0.18643 nm. To clearly display the properties of this electronic state, we depict the PEC in Fig. 1, and demonstrate the effects on the spectroscopic parameters of the 12 C 16 O + species by the core-valence correlation and/or relativistic corrections in Table Table 8 Spectroscopic parameters of the a 4 R + , 1 4 4, 1 4 R À and b 4 P electronic states of the 12 C 16 O + species determined by the MRCI+Q/AV5Z+CV+DK ...
Citations
... Since 1966, potential energy curves (PECs) for many electronic states of CO + have been published, obtained from RKR experimental data or ab initio theoretical calculations [14][15][16][17][18][19][20][21]. However, there are few, and not very accurate, models of analytical potential energy functions without adjustable coefficients, mainly for the excited states of CO + . ...
Accurate functions to analytically represent the potential energy interactions of CO+ diatomic system in X 2∑+, A2∏ and B 2∑+electronic states are proposed. The new functions depend upon only four parameters directly obtained from experimental data, without any fitting procedure. These functions have been developed from the modified generalized potential proposed by Araújo and Ballester [Phys. Scr. 96, 125407 (2021)]. The function for the X 2∑+ electronic state represents a significant improvement to the previously proposed model. To quantify the accuracy of the potential energy functions, the least-squares Z-test method, proposed by Murrell and Sorbie, is used. Furthermore, the main spectroscopic constants and vibrational energy levels are calculated and compared for all potentials. The present results agree excellently with the experiment Rydberg-Klein-Rees (RKR) potentials.
... Potential energy curves of CO and CO + have been reported by many using various methods [14][15][16]. Spectroscopic investigations, transition dipole moments calculations, and spin-orbit coupling studies present in the literature [17][18][19] show the importance of the diatom. There has also been some interest in exploring the bound state ion, [HeCO] + , resulting from the interaction of CO + with He, and ab initio calculations have been reported around the equilibrium geometries of [HeCO] + in its ground and first excited states [20][21][22]. ...
... Ab initio PECs of these excited states of CO + have been computed at MRCI/aug-cc-pVQZ level of theory and plotted in Fig. 1. Many refined calculations are available in the literature on the ground and electronic states of CO + [14,16,18,19]. We have compared the structural characteristics of CO and CO + in Table 1 to determine the precision of the current computations using the employed basis set. ...
... We have compared the structural characteristics of CO and CO + in Table 1 to determine the precision of the current computations using the employed basis set. The r e and T e values are in good agreement with experiments of Herzberg et al. [31] and the most recent and refined calculations of Shi et al. [18] and Xing et al. [19]. Table 1 Comparison of diatomic constants r e : the equilibrium bond length, T e : the vertical ionization potential of CO and CO + . ...
... Looking at the above set of small molecular cations, CO + has already been extensively explored with theoretical approaches [14][15][16] and many of its spectroscopic constants are well characterized experimentally [17,18]. However, because it is a small system similar to H 2 O + and H 2 CO + , it should act as a reasonable benchmark for electronically excited state methods that may then be applied to the latter molecules. ...
... TheB 2 Σ + state value is 53604 MHz, while there is a more significant shift for the à 2 Π state at 46983.5 MHz. Although data from previous theory are available [15] since CO+ is a simple diatomic, the high level anharmonic treatment from established QFF approaches provided here should be useful in fully modeling CO + spectra. Table 4 for F12-TZ, CcCR, and the family of EOM-IP QFFs, agree excellently with the given experimental data for theX 2 B 1 ground state of H 2 O + . ...
New high-level ab initio quartic force field (QFF) methods are explored which provide spectroscopic data for the electronically excited states of the carbon monoxide, water, and formaldehyde cations, sentinel species for expanded, recent cometary spectral analysis. QFFs based on equation-of-motion ionization potential (EOM-IP) with a complete basis set extrapolation and core correlation corrections provide assignment for the fundamental vibrational frequencies of the A˜2B1 and B˜2A1 states of the formaldehyde cation; only three of these frequencies have experimental assignment available. Rotational constants corresponding to these vibrational excitations are also provided for the first time for all electronically excited states of both of these molecules. EOM-IP-CCSDT/CcC computations support tentative re-assignment of the ν1 and ν3 frequencies of the B˜2B2 state of the water cation to approximately 2409.3 cm−1 and 1785.7 cm−1, respectively, due to significant disagreement between experimental assignment and all levels of theory computed herein, as well as work by previous authors. The EOM-IP-CCSDT/CcC QFF achieves agreement to within 12 cm−1 for the fundamental vibrational frequencies of the electronic ground state of the water cation compared to experimental values and to the high-level theoretical benchmarks for variationally-accessible states. Less costly EOM-IP based approaches are also explored using approximate triples coupled cluster methods, as well as electronically excited state QFFs based on EOM-CC3 and the previous (T)+EOM approach. The novel data, including vibrationally corrected rotational constants for all states studied herein, provided by these computations should be useful in clarifying comet evolution or other remote sensing applications in addition to fundamental spectroscopy.
... Theoretically, there is a vast amount of studies in the literature [24][25][26][27][28] , in which the potential interaction of low-lying electronic states are explored through different methodologies as well as spectroscopic parameters such as evaluated. In particular, vibronic (vibration-electronic) transition parameters as Franck-Condon factors, Einstein A coefficients and transition dipole moments (TDM) are shown in the paper of Xing et al. [27] . ...
In this article, a new study of the 12C16O First Negative system (B X), is performed both theoretically and experimentally. From an experimental point of view, high-resolution Fourier transform spectroscopy in the ultraviolet region was used. On the theoretical side, ab initio electronic energies were calculated employing the state-averaged multiconfiguration self-consistent field (MCSCF) method, followed by the icMRCI/AV6Z level of theory with Davidson modification. Through these two analyses, theoretical and experimental, values for the spectroscopic constants, potential energy curves, and parameters concerning the transition are presented. The results, both theoretical and experimental, obtained in this work are compared with values obtained in previous works, pointing out certain discrepancies with more recent works and providing new and improved values for the band origins of this transition.
... Interaction energies of these states are thus descending asymptotically to zero, while the interaction energy of the 1 2 − state rises to zero, which is also reflected in the values of the C 3 coefficients. In general, our equilibrium distances are in good agreement with experimental results (Huber & Herzberg 1979;Cossart & Cossart-Magos 1990) and also with theoretical results of Okada & Iwata (2000), Marshall (2008), and Shi et al. (2011). ...
Radiative association of an oxygen atom with a carbon cation is investigated using quantal and semiclassical methods. The total rate coefficient for spontaneous radiative association of O(2s22p4, 3P) with C+(2s22p, 2P) on the doublet manifold is determined from the corresponding cross-sections. The cross-sections for the ${\rm 1}^2\, \Sigma ^-\rightarrow {\rm A}^2\Pi$, ${\rm 2}^2\, \Sigma ^-\rightarrow {\rm A}^2\Pi$, and ${\rm C}^2\, \Delta \rightarrow {\rm A}^2\Pi$ continuum-bound processes are calculated either semiclassically, in combination with the Breit–Wigner approach, or fully quantum mechanically. In the temperature range 10–10 000 K, our recommended total rate coefficient, obtained from these calculations and the data of Zámečníková et al. (2019), slowly increases from 7.5 × 10−18 cm3s−1 to 2.1 × 10−17 cm3s−1. Corresponding aspects of the CO+ and CO formations in SN 1987A are discussed.
... The study has going on and a number of theoretical studies have been done for different electronic states of CO + molecules which include Marian et al. in 1989 [19], Lavendy et al. [20], Martin et al. [21] and many others. The theoretical study also has been done by Okada and Iwata, in 2000 [22], Vazquez et al. in 2009 [23], Shi et al. in 2011 [24] and others [25,26]. In this paper, we present our work in comparison to the available experimental and theoretical results using MRDCI method. ...
The potential energy curves of 2 + , 2 , 2 + , C and 2 D electronic states of CO + ion have been calculated using the multi-reference single and double excitation configuration-interaction method (MRDCI). The potential energy curves and transition dipole moment have been calculated in the range of 1.6 to 7.0 a0 internuclear distance (R). The calculated potential energy curves found to converge smoothly to the correct dissociation channel. The potential energy curves and transition dipole moment are used as the input in the Level 8.0 program of R. J. Le Roy for the spectroscopic studies of CO + ion.
... And the ab-initio potential curves of a 4 Σ + , D 2 Πi, 1 2 Σ -, E 2 Σ + , F 2 Δr are directly selected from Ref. [51]. Klein-Dunham coefficients for X 2 Σ + , A 2 Πi, B 2 Σ + can be found in our previous publication [30] [42,57]. Klein-Dunham coefficients for X 2 Σ + , A 2 Πi, B 2 Σ + can be found in our previous publication [30] ...
The level energies of diatomic molecules calculated by the frequently used Dunham expansion will become less accurate for high-lying vibrational and rotational levels. In this paper, the potential curves for the lower-lying electronic states with accurate spectroscopic constants are reconstructed using the Rydberg-Klein-Rees (RKR) method, which are extrapolated to the dissociation limits by fitting of the theoretical potentials, and the rest of the potential curves are obtained from the ab-initio results in the literature. Solving the rotational dependence of the radial Schrödinger equation over the obtained potential curves, we determine the rovibrational level energies, which are then used to calculate the equilibrium and non-equilibrium thermodynamic properties of N2, View the MathML source, NO, O2, CN, C2, CO and CO+. The partition functions and the specific heats are systematically validated by available data in the literature. Finally, we calculate the radiative source strengths of diatomic molecules in thermodynamic equilibrium, which agree well with the available values in the literature. The spectral radiative intensities for some diatomic molecules in thermodynamic non-equilibrium are calculated and validated by available experimental data.
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The reliable data of plasma thermodynamic properties are of vital significance for aerodynamic modelling and plasma dynamics simulation. In this work, we have thoroughly evaluated the thermodynamic properties of diatomic CO, CN, C2 and CO⁺ by making use of a more rigorous approach. The internal energy levels were precisely determined by solving rotational dependence of the radial Schrödinger equation over a set of potential curves. The RKR method was used to generate the low-lying potential curves, while the ab initio results reported by the recent publications were selected for the potential curves of high-lying states. More electronic states were considered in this work than in previous publications, which helps to make the calculated results more accurate at high temperatures. The predicted results were verified by the available values in the recent studies and the relative deviations were systematically evaluated. The maximum relative difference of the equilibrium partition function is less than 7.7% for all species and not larger than 15.3% for equilibrium dimensionless specific heat.
The thermodynamic and transport properties of magnesium oxide crystal arc plasma have been researched under local thermodynamic equilibrium in this paper. The pure CO2 plasma in the arc initiation stage and Mg-CO mixtures plasma in the stable melting stage were selected. The parameter-variation method combined with Levenberg–Marquardt algorithm (PVM-LMA) is used to solve the plasma equilibrium compositions model established by mass action law from higher to lower temperature in sequence. Taking Mg50%-CO50% plasma as an example, the plasma number density of 7500 K is calculated according to 8000 K. The results show that the PVM-LMA algorithm has the advantages of fast and high precision The comparisons to the results of pure CO2 in previous literature are displayed and our work shows better agreement with theirs. The results of Mg-CO mixtures indicate that the chemical properties of Mg atoms are more active and easier to ionize, which can effectively improve the electrical conductivity and thermal conductivity of plasma and reduce its viscosity.
