Based on the two-component relativistic effective core potential and matched basis sets cc-pwcvnz-pp (n=Q, 5), combining the completed basis-set extrapolation of electronic correlation energy and the fourth-order po...Based on the two-component relativistic effective core potential and matched basis sets cc-pwcvnz-pp (n=Q, 5), combining the completed basis-set extrapolation of electronic correlation energy and the fourth-order polynomial fitting technique, the bond length and spectroscopic constants of Hg2 are studied by the coupled cluster theory with spin-orbit coupling. Spin-orbit coupling is included in the post Hartree-Fock procedure, i.e., in the coupled- cluster iteration, to obtain more reliable theoretical results. The results show that our theoretical values agree with the experimental values very well and will be helpful to understand the spectral character of Hg2.展开更多
The SiS molecule,which plays a significant role in space,has attracted a great deal of attention for many years.Due to complex interactions among its low-lying electronic states,precise information regarding the molec...The SiS molecule,which plays a significant role in space,has attracted a great deal of attention for many years.Due to complex interactions among its low-lying electronic states,precise information regarding the molecular structure of SiS is limited.To obtain accurate information about the structure of its excited states,the high-precision multireference configuration interaction(MRCI)method has been utilized.This method is used to calculate the potential energy curves(PECs)of the 18Λ–S states corresponding to the lowest dissociation limit of SiS.The core–valence correlation effect,Davidson’s correction and the scalar relativistic effect are also included to guarantee the precision of the MRCI calculation.Based on the calculated PECs,the spectroscopic constants of quasi-bound and bound electronic states are calculated and they are in accordance with previous experimental results.The transition dipole moments(TDMs)and dipole moments(DMs)are determined by the MRCI method.In addition,the abrupt variations of the DMs for the 1^(5)Σ^(+)and 2^(5)Σ^(+)states at the avoided crossing point are attributed to the variation of the electronic configuration.The opacity of SiS at a pressure of 100 atms is presented across a series of temperatures.With increasing temperature,the expanding population of excited states blurs the band boundaries.展开更多
The 18 A-S states correlated to the lowest dissociation limit of SiTe were calculated by using a high-level multirefer-ence configuration interaction (MRCI) method, including scalar relativistic and spin-orbit coupl...The 18 A-S states correlated to the lowest dissociation limit of SiTe were calculated by using a high-level multirefer-ence configuration interaction (MRCI) method, including scalar relativistic and spin-orbit coupling effects. Based on the calculated potential energy curves, the spectroscopic constants of bound states were determined, which are well consistent with previous experimental results. The spin-orbit matrix elements between the A-S states were computed, which lead to an in-deoth understanding, of oerturbations on the electronic state a^3∏. Finally. the transition dioole moments of allowed transitionsA^1∏-X^1∑^+,E^1∑^+-X^1∑^+,a^3∏-d^3△,a^3∏-d^3△,a^∏-a′^3∑^+,a^3∏-e^3∑^-,and the radiative lifetimes of A^1∏,E^1∑^+,and a^3∏ were evaluated.展开更多
This paper calculates the equilibrium internuclear separations, the harmonic frequencies and the potential energy curves of the X^2∑+, A^2П and B^2∑+ states of the CP radical by the highly accurate valence intern...This paper calculates the equilibrium internuclear separations, the harmonic frequencies and the potential energy curves of the X^2∑+, A^2П and B^2∑+ states of the CP radical by the highly accurate valence internally contracted multireference configuration interaction method with correlation-consistent basis sets (aug-cc-pV6Z for C atom and aug-cc-pVQZ for P atom). The potential energy curves are all fitted with the analytic potential energy function by the least-square fitting. Employing the analytic potential energy function, we determine the spectroscopic constants (Be, αe and ωeχe) of these states. For the X2∑+ state, the obtained values of De, Be, αe, ωeχe, Re and ωe are 5.4831 eV, 0.792119 cm-1, 0.005521 cm-1, 6.89653 cm-1, 0.15683 nm, 12535.11 cm-1, respectively. For the A2H state, the present values of De, Be,αe, ωeχe, Re and We are 4.586 eV, 0.703333 cm-1, 0.005458 cm-1, 6.03398 cm-1, 0.16613 nm, 1057.89 cm-1, respectively. For the B2E+ state, the present values of De, Be, αe, ωeχe, Re and We are 3.506 eV, 0.677561 cm-1, 0.00603298 cm-1, 5.68809 cm-1, 0.1696 nm, 822.554 cm-1, respectively. For these states, the vibrational states with the rotational quantum number J equals zero (J = 0) are studied by solving the radial nuclear Schr6dinger equation using the Numerov method. For each vibrational state, the vibrational level, the classical turning points, the rotational inertial and the centrifugal distortion constants are calculated. Comparison is made with recent theoretical and experimental results.展开更多
The splitting of potential energy curves for the states X^2Ⅱ3/2, ^2Ⅱ1/2 and A^2∑+ of hydroxyl OH under spin-orbit coupling (SOC) has been calculated by using the SO multi-configuration quasi-degenerate perturbat...The splitting of potential energy curves for the states X^2Ⅱ3/2, ^2Ⅱ1/2 and A^2∑+ of hydroxyl OH under spin-orbit coupling (SOC) has been calculated by using the SO multi-configuration quasi-degenerate perturbation theory (SO- MCQDPT). Their Murrell Sorbic (M-S) potential functions have been derived, then, the spectroscopic constants for X^2Ⅱ3/2, ^2Ⅱ1/2 and A^2∑+ have been derived from the M-S function. The calculated dissociation energies for the three states are Do[OH(X^2Ⅱ3/2)]=34966,632cm^-1, Do[OH(^2Ⅱ1/2)]=34922.802cm^-1, and Do[OH(A^2∑ )]=17469.794cm^-1, respectively. The vertical excitation energy u[^2Ⅱ1/2(v = 0) → X^2Ⅱ3/2(v = 0)] = 139.6cm^-1. All the spectroscopic data for the X^2Ⅱ3/2 and ^2Ⅱ1/2 are given for the first time except the dissociation energy of X^2Ⅱ3/2.展开更多
This paper reports that the splitting of potential energy curves for the low-lying or low excited states for hydride molecules (cations) (MgH, AlH^+, SiH, PH^+, SH,ClH^+) of the third period under Spin-Orbit Co...This paper reports that the splitting of potential energy curves for the low-lying or low excited states for hydride molecules (cations) (MgH, AlH^+, SiH, PH^+, SH,ClH^+) of the third period under Spin-Orbit Coupling has been calculated by using the Spin-Orbit Multi-Configuration Quasi-Degenerate Perturbation Theory (SO-MCQDPT) method. Then, spectroscopic constants of the split states have been derived from the Murrell-Sorbie function. The calculated dissociation energies for the spectrum branch terms have been given, respectively. The spectroscopic constants and dissociation energies for the spectrum branch terms are given for the first time in this paper.展开更多
This paper applies the symmetry-aziapted-cluster/symmetry-adapted-cluster configuration-interaction (SAC/SACCI) method to optimize the structures for X^1∑^+, A^1 Ⅱ and C^1 ∑^- states of SiO molecule with the bas...This paper applies the symmetry-aziapted-cluster/symmetry-adapted-cluster configuration-interaction (SAC/SACCI) method to optimize the structures for X^1∑^+, A^1 Ⅱ and C^1 ∑^- states of SiO molecule with the basis sets D95++, 6-311++G and 6-311++G^**. Comparing the obtained results with the experiments, it gets the conclusion that the basis set 6-311++G^** is most suitable for the optimal structure calculations of X^1.∑^+, A^Ⅱ and C^1∑^- states of SiO molecule. The whole potential energy curves for these electronic states are further scanned by using SAC/6-311++G^** method for the ground state and SAC-CI/6-311++G^** method for the excited states, then use a least square method to fit Murrell^Sorbie functions, at last the spectroscopic constants and force constants are calculated, which are in good agreement with the experimental data.展开更多
This paper applies the density functional theory method to optimise the structure for X3A state of TiO molecule with the basis sets 6-31G, 6-31++G and 6-311G^**. Comparing the attained results with the experiments...This paper applies the density functional theory method to optimise the structure for X3A state of TiO molecule with the basis sets 6-31G, 6-31++G and 6-311G^**. Comparing the attained results with the experiments, it obtains the conclusion that the basis set 6-31++G is most suitable for the optimal structure calculations of X3A state of TiO molecule. The whole potential energy curve for the electronic state is further scanned by using B3P86/6-31++G method for the ground state, then it uses a least square fitted to Murrell-Sorbie functions, at last it calculates the spectroscopic constants and force constants, which are in better agreement with the experimental data.展开更多
The high accuracy ab initio calculation method of multi-reference configuration interaction(MRCI) is used to compute the low-lying eight electronic states of CuN.The potential energy curves(PECs) of the X;∑;,1;Π...The high accuracy ab initio calculation method of multi-reference configuration interaction(MRCI) is used to compute the low-lying eight electronic states of CuN.The potential energy curves(PECs) of the X;∑;,1;Π,2;∑;,1;△,1;△,1;∑;,1;Π,and;∑;in a range of R=0.1 nm-0.5 nm are obtained and they are goodly asymptotes to the Cu(;S;) + N(;S;) and Cu(;S;)+N(;D;) dissociation limits.All the possible vibrational levels,rotational constants,and spectral constants for the six bound states of X;∑;,1;Π,2;∑;,1;△,1;∑;,and 1;Π are obtained by solving the radial Schrdinger equation of nuclear motion with the Le Roy provided Level 8.0 program.Also the transition dipole moments from the ground state X;∑;to the excited states 1;Π and 2;∑;are calculated and the result indicates that the 2;∑-X;∑ transition has a much higher transition dipole moment than the 1;Π-X;∑;transition even though the l;Π state is much lower in energy than the 2;∑;state.展开更多
A globally accurate potential energy surface is reported for the electronic ground-state H2O+. The ab initio energies utilized to map the potential energy surface are calculated at the multireference configuration in...A globally accurate potential energy surface is reported for the electronic ground-state H2O+. The ab initio energies utilized to map the potential energy surface are calculated at the multireference configuration interaction method employing the aug-cc-pVQZ basis set and the full valence complete active space wave function as reference. In order to improve accu- racy of the resulting raw ab initio energies, they are then extrapolated to the complete basis set limit and most importantly to the full configuration-interaction limit by semiempirically correcting the dynamical correlation using the double many- body expansion-scaled external correlation method. The topographical features of the current potential energy surface were examined in detail, which agree nicely with those of other theoretical work.展开更多
Multireference configuration interaction calculations are carried out on 11 Λ–S low-lying electronic states of indium dimers. The states are investigated with spin–orbit pseudopotentials via the state-interacting m...Multireference configuration interaction calculations are carried out on 11 Λ–S low-lying electronic states of indium dimers. The states are investigated with spin–orbit pseudopotentials via the state-interacting method, and characterized by fitted spectroscopic constants based on computed potential energy curves. The vibrational structures of the double-potential well 0^+g (I) ( ^3 Σ g^- ) state are also analyzed. The experimentally observed absorption spectrum centred at ~ 13000cm-1 is simulated and assigned to X 3 Πu (v'=0)–3Πg transition according to the present ab initio calculations on transition energies and dipole moment functions.展开更多
The SF radical and its singly charged cation and anion, SF+ and SF-, have been investigated on the MRCI/aug-cc- pVXZ (X = Q, 5, 6) levels of theory with Davidson correction. Both the core-valence correlation and th...The SF radical and its singly charged cation and anion, SF+ and SF-, have been investigated on the MRCI/aug-cc- pVXZ (X = Q, 5, 6) levels of theory with Davidson correction. Both the core-valence correlation and the relativistic effect are considered. The extrapolating to the complete basis set (CBS) limit is adopted to remove the basis set truncation error. Geometrical parameters, potential energy curves (PECs), vibrational energy levels, spectroscopic constants, ionization po- tentials, and electron affinities of the ground electronic state for all these species are obtained. The information with respect to molecular characteristics of the SFn (n = -1, 0, + 1) systems derived in this work will help to extend our knowledge and to guide further experimental or theoretical researches.展开更多
Potential energy curves of the X^(1)Σ+and A;Πstates of the Al F molecule are studied through the combination of the multi-reference configuration interaction(MRCI)approach and Davidson corrections(MRCI+Q).The AWCV5 ...Potential energy curves of the X^(1)Σ+and A;Πstates of the Al F molecule are studied through the combination of the multi-reference configuration interaction(MRCI)approach and Davidson corrections(MRCI+Q).The AWCV5 Z basis set is employed in the calculations.The transition dipole moments(TDMs)of the A;Π■X^(1)Σ+transition are explored based on the AWCV5 Z basis set and(4,2,2,0)active space.The Schrödinger equation is solved via the LEVEL 8.2 program,and the vibrational levels and rotational constants of the X^(1)Σ+and A1Πstates are calculated.It is shown that the Al F molecule has high diagonal Franck-Condon factors(f00=0.9949 and f11=0.9854)and large Einstein coefficients for the transition of A;Π(ν′=0)■X^(1)Σ+(ν′′=0).In addition,the radiative lifetimes of the vibrational levels are close to 10-9 s for the A;Πstate.The line intensities of the A;Π(ν′=4-15)■X^(1)Σ+(ν′′=0)transitions are also calculated.The calculated TDMs and transition probabilities in this work are credible and provide some guidance for the study of similar transitions,particularly for exploring interstellar space.展开更多
The high level quantum chemistry ab inito multi-reference configuration interaction (MRCI) method with large V5Z basis set is used to calculate the spectroscopic properties of the 15 A-S electronic states (X1∑+, ...The high level quantum chemistry ab inito multi-reference configuration interaction (MRCI) method with large V5Z basis set is used to calculate the spectroscopic properties of the 15 A-S electronic states (X1∑+, A I П, 1 △, 1 ∑, 3∑+, 3П, 3△, 3△ , 5∑+, 5П, 5△, 1П (II), ofAsO+ radical correlated to the dissociation limit As+(3pg) + O(3pg) and As+(IDg) + O(1Dg). In order to obtain better potential curves and more accurate spectroscopic properties, the Davidson modification is taken into account. With the potential energy curves (PECs) determined here, vibrational levels G(v) and inertial rotation constants Bu are computed for all the bound electronic states when the rotational quantum number J equals zero (J = 0). Except for the states X1∑+, A1П , it is the first time that the multi-reference configuration calculation has been used on the 13 A-S electronic states of the AsO+ radical. The potential energy curves of all the A-S electronic states are depicted according to the avoided crossing rule of the same symmetry. Spin-orbit coupling effect (SOC) is introduced into the states X1 ∑+, A1 П, 3П to consider its effects on the spectroscopic properties. Transition dipole moments (TDMs) from A1П 1, 3 П1 states to the ground state X1∑0+ are predicted as well.展开更多
The feasibility of laser cooling a CH molecule is investigated theoretically by employing the ab initio method. The potential energy curves for the five ∧-S states and eight Ω states of CH are determined by the mult...The feasibility of laser cooling a CH molecule is investigated theoretically by employing the ab initio method. The potential energy curves for the five ∧-S states and eight Ω states of CH are determined by the multi-reference configuration interaction with the Davidson corrections(MRCI+Q) level of theory. The results agree well with the available experimental data and other theoretical values. Also, the permanent dipole moments and transition dipole moments of the CH molecule are calculated at the multi-reference configuration interaction(MRCI) level. We find highly diagonally distributed FranckCondon factors(f00 = 0.9950 and 0.9998) and branching ratios(R00 = 0.983 and 0.993) for the A^2△→ X2Π and C^2∑^+→X^2Π transitions. Moreover, the values of suitable radiative lifetime τ of the A2 A and C^2∑^+ states are evaluated to be9.64×10^-7 s and 2.02×10^-7 s, respectively, for rapid laser cooling. A scheme for laser cooling the CH molecule is designed. In the proposed cooling scheme, three wavelengths for A^2△→X^2Π and C^2∑^+→X^2Π transitions are used, and the main pump lasers are λ00=430.86 nm and 313.45 nm, respectively. The feasibility of laser cooling the CH molecules is demonstrated for each of these schemes, and this study offers a theoretical basis for experimental research into preparation of cold CH molecules.展开更多
Potential energy curves (PECs) for the ground state (X2∑+) and the four excited electronic states (A2∏, B2∏, C2∑+, 4∏) of a Bell molecule are calculated using the multi-configuration reference single and ...Potential energy curves (PECs) for the ground state (X2∑+) and the four excited electronic states (A2∏, B2∏, C2∑+, 4∏) of a Bell molecule are calculated using the multi-configuration reference single and double excited configuration interaction (MRCI) approach in combination with the aug-cc-pVTZ basis sets. The calculation covers the internuclear distance ranging from 0.07 nm to 0.70 nm, and the equilibrium bond length Re and the vertical excited energy Te are determined directly. It is evident that the X2∑+, A2∏, B2∏, C2∑+ states are bound and 4∏ is a repulsive excited state. With the potentials, all of the vibrational levels and inertial rotation constants are predicted when the rotational quantum number J is set to be equal to zero (J = 0) by numerically solving the radial SchrSdinger equation of nuclear motion. Then the spectroscopic data are obtained including the rotation coupling constant w e, the anharmonic constant WeXe, the equilibrium rotation constant Be, and the vibration-rotation coupling constant ae. These values are compared with the theoretical and experimental results currently available, showing that they are in agreement with each other.展开更多
The feasibility of spin-forbidden cooling of the In H molecule is investigated based on ab initio quantum chemistry calculations. The potential energy curves for the X^1Σ0^+^+, a^3Π0-, a^3Π0^+, a^3Π1, a-3Π2, ...The feasibility of spin-forbidden cooling of the In H molecule is investigated based on ab initio quantum chemistry calculations. The potential energy curves for the X^1Σ0^+^+, a^3Π0-, a^3Π0^+, a^3Π1, a-3Π2, A-1Π1, 1-3Σ^0^-+, and 1-3Σ1-+states of In H are obtained based on multi-reference configuration interaction plus the Davidson corrections method. The calculated spectroscopic constants are in good agreement with the available experimental data. In addition, the influences of the active space and spin–orbit coupling effects on the potential energy curves and spectroscopic constants are also studied. For Re of a^3Π0^-, a^3Π0^+, a^3Π1, and a-3Π2 states, the error from large active space is small. The potential energy curve of the A-1Π1state is not smooth for small active space. The spin–orbit coupling effects have great influences on the potential well depth and equilibrium internuclear distance of the A-1Π state. The Franck–Condon factors and radiative lifetimes are obtained on the basis of the transition dipole moments of the a^3Π0^+)→ X^1Σ0^+^+, a-3Π1 → X-1Σ0^+-+, and A-1Π1 → X-1Σ0^+^+ transitions. Our calculation indicates that the a^3Π1( ν'= 0) → X-1Σ0^+^+(ν = 0) transition provides a highly diagonally distributed Franck–Condon factor and a short radiative lifetime for the a3Π1 state, which can ensure rapid and efficient laser cooling of In H.The proposed laser drives a-3Π1 → X-1Σ0^+^+ transitions by using three wavelengths.展开更多
The potential energy curves for neutrals and multiply charged ions of carbon monosulfide are computed with highly correlated multi-reference configuration interaction wavefunctions.The correlations of inner-shell elec...The potential energy curves for neutrals and multiply charged ions of carbon monosulfide are computed with highly correlated multi-reference configuration interaction wavefunctions.The correlations of inner-shell electrons with the scalar relativistic effects are included in the present computations.The spectroscopic constants,dissociation energies,ionization energies for ground and low-lying excited states together with corresponding electronic configurations of ions are obtained,and a good agreement between the present work and existing experiments is found.No theoretical evidence is found for the adiabatically stable CSq+(q〉2) ions according to the present ab initio calculations.The calculated values for 1st-6th ionization energies are 11.25,32.66,64.82,106.25,159.75,and 224.64 eV,respectively.The kinetic energy release data of fragments are provided by the present work for further experimental comparisons.展开更多
The potential energy curves (PECs) of the16 lowest electronic states in the representation <sup>2s+1</sup>Λ<sup> (+/-)</sup> of the molecule ScTe have been investigated via ab initio CASSCF an...The potential energy curves (PECs) of the16 lowest electronic states in the representation <sup>2s+1</sup>Λ<sup> (+/-)</sup> of the molecule ScTe have been investigated via ab initio CASSCF and MRCI (single and double excitations with Davidson correction) calculations. The permanent dipole moment curves (PDMCs) and the spectroscopic constants such as vibrational harmonic frequency ω<sub>e</sub>, the internuclear distance at equilibrium R<sub>e</sub>, the rotational constant B<sub>e</sub>, and the electronic transition energy T<sub>e</sub> with respect to the ground state have been calculated for the different bound investigated electronic states. The comparison of the present results with the rare available theoretical data in literature shows an overall good agreement. To the best of our knowledge, 15 electronic states of the ScTe molecule are not yet investigated either experimentally or theoretically, they are investigated in the present work for the first time.展开更多
基金Supported by the Start-Up Funds of Xi’an Polytechnic University under Grant No BS1211the Scientific Research Program Funded by Shaanxi Provincial Education Department under Grant No 2013JK0679
文摘Based on the two-component relativistic effective core potential and matched basis sets cc-pwcvnz-pp (n=Q, 5), combining the completed basis-set extrapolation of electronic correlation energy and the fourth-order polynomial fitting technique, the bond length and spectroscopic constants of Hg2 are studied by the coupled cluster theory with spin-orbit coupling. Spin-orbit coupling is included in the post Hartree-Fock procedure, i.e., in the coupled- cluster iteration, to obtain more reliable theoretical results. The results show that our theoretical values agree with the experimental values very well and will be helpful to understand the spectral character of Hg2.
基金Project supported by the Natural Science Foundation of Heilongjiang Province,China(Grant No.LH2022A026)the National Key Research and Development Program of China(Grant No.2022YFA1602500)+2 种基金the National Natural Science Foundation of China(Grant No.11934004)Fundamental Research Funds in Heilongjiang Province Universities,China(Grant No.145109309)Foundation of National Key Laboratory of Computational Physics(Grant No.6142A05QN22006)。
文摘The SiS molecule,which plays a significant role in space,has attracted a great deal of attention for many years.Due to complex interactions among its low-lying electronic states,precise information regarding the molecular structure of SiS is limited.To obtain accurate information about the structure of its excited states,the high-precision multireference configuration interaction(MRCI)method has been utilized.This method is used to calculate the potential energy curves(PECs)of the 18Λ–S states corresponding to the lowest dissociation limit of SiS.The core–valence correlation effect,Davidson’s correction and the scalar relativistic effect are also included to guarantee the precision of the MRCI calculation.Based on the calculated PECs,the spectroscopic constants of quasi-bound and bound electronic states are calculated and they are in accordance with previous experimental results.The transition dipole moments(TDMs)and dipole moments(DMs)are determined by the MRCI method.In addition,the abrupt variations of the DMs for the 1^(5)Σ^(+)and 2^(5)Σ^(+)states at the avoided crossing point are attributed to the variation of the electronic configuration.The opacity of SiS at a pressure of 100 atms is presented across a series of temperatures.With increasing temperature,the expanding population of excited states blurs the band boundaries.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11034003,11074095,and 11274140)the Natural Science Foundation of Heilongjiang Province,China(Grant No.F201335)the Scientific and Technological Research Foundation of Qiqihar,China(Grant No.GYGG-201209-1)
文摘The 18 A-S states correlated to the lowest dissociation limit of SiTe were calculated by using a high-level multirefer-ence configuration interaction (MRCI) method, including scalar relativistic and spin-orbit coupling effects. Based on the calculated potential energy curves, the spectroscopic constants of bound states were determined, which are well consistent with previous experimental results. The spin-orbit matrix elements between the A-S states were computed, which lead to an in-deoth understanding, of oerturbations on the electronic state a^3∏. Finally. the transition dioole moments of allowed transitionsA^1∏-X^1∑^+,E^1∑^+-X^1∑^+,a^3∏-d^3△,a^3∏-d^3△,a^∏-a′^3∑^+,a^3∏-e^3∑^-,and the radiative lifetimes of A^1∏,E^1∑^+,and a^3∏ were evaluated.
基金supported by the National Natural Science Foundation of China (Grant No. 10874064)the Program for Science & Technology Innovation Talents in Universities of Henan Province in China (Grant No. 2008HASTIT008)
文摘This paper calculates the equilibrium internuclear separations, the harmonic frequencies and the potential energy curves of the X^2∑+, A^2П and B^2∑+ states of the CP radical by the highly accurate valence internally contracted multireference configuration interaction method with correlation-consistent basis sets (aug-cc-pV6Z for C atom and aug-cc-pVQZ for P atom). The potential energy curves are all fitted with the analytic potential energy function by the least-square fitting. Employing the analytic potential energy function, we determine the spectroscopic constants (Be, αe and ωeχe) of these states. For the X2∑+ state, the obtained values of De, Be, αe, ωeχe, Re and ωe are 5.4831 eV, 0.792119 cm-1, 0.005521 cm-1, 6.89653 cm-1, 0.15683 nm, 12535.11 cm-1, respectively. For the A2H state, the present values of De, Be,αe, ωeχe, Re and We are 4.586 eV, 0.703333 cm-1, 0.005458 cm-1, 6.03398 cm-1, 0.16613 nm, 1057.89 cm-1, respectively. For the B2E+ state, the present values of De, Be, αe, ωeχe, Re and We are 3.506 eV, 0.677561 cm-1, 0.00603298 cm-1, 5.68809 cm-1, 0.1696 nm, 822.554 cm-1, respectively. For these states, the vibrational states with the rotational quantum number J equals zero (J = 0) are studied by solving the radial nuclear Schr6dinger equation using the Numerov method. For each vibrational state, the vibrational level, the classical turning points, the rotational inertial and the centrifugal distortion constants are calculated. Comparison is made with recent theoretical and experimental results.
基金Project supported by the National Natural Science Foundation of China (Grant No 10376022).
文摘The splitting of potential energy curves for the states X^2Ⅱ3/2, ^2Ⅱ1/2 and A^2∑+ of hydroxyl OH under spin-orbit coupling (SOC) has been calculated by using the SO multi-configuration quasi-degenerate perturbation theory (SO- MCQDPT). Their Murrell Sorbic (M-S) potential functions have been derived, then, the spectroscopic constants for X^2Ⅱ3/2, ^2Ⅱ1/2 and A^2∑+ have been derived from the M-S function. The calculated dissociation energies for the three states are Do[OH(X^2Ⅱ3/2)]=34966,632cm^-1, Do[OH(^2Ⅱ1/2)]=34922.802cm^-1, and Do[OH(A^2∑ )]=17469.794cm^-1, respectively. The vertical excitation energy u[^2Ⅱ1/2(v = 0) → X^2Ⅱ3/2(v = 0)] = 139.6cm^-1. All the spectroscopic data for the X^2Ⅱ3/2 and ^2Ⅱ1/2 are given for the first time except the dissociation energy of X^2Ⅱ3/2.
基金Project supported by the National Natural Science Foundation of China (Grant No 10376022)
文摘This paper reports that the splitting of potential energy curves for the low-lying or low excited states for hydride molecules (cations) (MgH, AlH^+, SiH, PH^+, SH,ClH^+) of the third period under Spin-Orbit Coupling has been calculated by using the Spin-Orbit Multi-Configuration Quasi-Degenerate Perturbation Theory (SO-MCQDPT) method. Then, spectroscopic constants of the split states have been derived from the Murrell-Sorbie function. The calculated dissociation energies for the spectrum branch terms have been given, respectively. The spectroscopic constants and dissociation energies for the spectrum branch terms are given for the first time in this paper.
基金Project supported by the Basic Research Program of Education Bureau of Henan Province of China (Grant No 2008A140006)
文摘This paper applies the symmetry-aziapted-cluster/symmetry-adapted-cluster configuration-interaction (SAC/SACCI) method to optimize the structures for X^1∑^+, A^1 Ⅱ and C^1 ∑^- states of SiO molecule with the basis sets D95++, 6-311++G and 6-311++G^**. Comparing the obtained results with the experiments, it gets the conclusion that the basis set 6-311++G^** is most suitable for the optimal structure calculations of X^1.∑^+, A^Ⅱ and C^1∑^- states of SiO molecule. The whole potential energy curves for these electronic states are further scanned by using SAC/6-311++G^** method for the ground state and SAC-CI/6-311++G^** method for the excited states, then use a least square method to fit Murrell^Sorbie functions, at last the spectroscopic constants and force constants are calculated, which are in good agreement with the experimental data.
基金supported by the Basic Research Program of Education Bureau of Henan Province,China (Grant No.2010A140008)the National Natural Science Foundation of China (Grant No.10774039)the Natural Science Foundation of Henan Province,China (Grant No.092300410249)
文摘This paper applies the density functional theory method to optimise the structure for X3A state of TiO molecule with the basis sets 6-31G, 6-31++G and 6-311G^**. Comparing the attained results with the experiments, it obtains the conclusion that the basis set 6-31++G is most suitable for the optimal structure calculations of X3A state of TiO molecule. The whole potential energy curve for the electronic state is further scanned by using B3P86/6-31++G method for the ground state, then it uses a least square fitted to Murrell-Sorbie functions, at last it calculates the spectroscopic constants and force constants, which are in better agreement with the experimental data.
文摘The high accuracy ab initio calculation method of multi-reference configuration interaction(MRCI) is used to compute the low-lying eight electronic states of CuN.The potential energy curves(PECs) of the X;∑;,1;Π,2;∑;,1;△,1;△,1;∑;,1;Π,and;∑;in a range of R=0.1 nm-0.5 nm are obtained and they are goodly asymptotes to the Cu(;S;) + N(;S;) and Cu(;S;)+N(;D;) dissociation limits.All the possible vibrational levels,rotational constants,and spectral constants for the six bound states of X;∑;,1;Π,2;∑;,1;△,1;∑;,and 1;Π are obtained by solving the radial Schrdinger equation of nuclear motion with the Le Roy provided Level 8.0 program.Also the transition dipole moments from the ground state X;∑;to the excited states 1;Π and 2;∑;are calculated and the result indicates that the 2;∑-X;∑ transition has a much higher transition dipole moment than the 1;Π-X;∑;transition even though the l;Π state is much lower in energy than the 2;∑;state.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304185 and 11074151)China Postdoctoral Science Foundation(Grant No.2014M561957)+1 种基金the Postdoctoral Innovation Project of Shandong Province,China(Grant No.201402013)the Shandong Provincial Natural Science Foundation,China(Grant No.ZR2014AM022)
文摘A globally accurate potential energy surface is reported for the electronic ground-state H2O+. The ab initio energies utilized to map the potential energy surface are calculated at the multireference configuration interaction method employing the aug-cc-pVQZ basis set and the full valence complete active space wave function as reference. In order to improve accu- racy of the resulting raw ab initio energies, they are then extrapolated to the complete basis set limit and most importantly to the full configuration-interaction limit by semiempirically correcting the dynamical correlation using the double many- body expansion-scaled external correlation method. The topographical features of the current potential energy surface were examined in detail, which agree nicely with those of other theoretical work.
基金Project supported by the National Magnetic Confinement Fusion Science Program of China (Grant No. 2010GB104003)the Fundamental Research Funds for the Central Universities (Grant No. 450060481375)
文摘Multireference configuration interaction calculations are carried out on 11 Λ–S low-lying electronic states of indium dimers. The states are investigated with spin–orbit pseudopotentials via the state-interacting method, and characterized by fitted spectroscopic constants based on computed potential energy curves. The vibrational structures of the double-potential well 0^+g (I) ( ^3 Σ g^- ) state are also analyzed. The experimentally observed absorption spectrum centred at ~ 13000cm-1 is simulated and assigned to X 3 Πu (v'=0)–3Πg transition according to the present ab initio calculations on transition energies and dipole moment functions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304023 and 11447172)the Young and Middle-Aged Talent of Education Burea of Hubei Province,China(Grant No.Q20151307)the Yangtze Youth Talents Fund of Yangtze University,China(Grant No.2015cqr21)
文摘The SF radical and its singly charged cation and anion, SF+ and SF-, have been investigated on the MRCI/aug-cc- pVXZ (X = Q, 5, 6) levels of theory with Davidson correction. Both the core-valence correlation and the relativistic effect are considered. The extrapolating to the complete basis set (CBS) limit is adopted to remove the basis set truncation error. Geometrical parameters, potential energy curves (PECs), vibrational energy levels, spectroscopic constants, ionization po- tentials, and electron affinities of the ground electronic state for all these species are obtained. The information with respect to molecular characteristics of the SFn (n = -1, 0, + 1) systems derived in this work will help to extend our knowledge and to guide further experimental or theoretical researches.
基金supported by the National Natural Science Foundation of China(Grant No.11947127)the Shaanxi Natural Science Foundation,China(Grant No.2018JM1053)。
文摘Potential energy curves of the X^(1)Σ+and A;Πstates of the Al F molecule are studied through the combination of the multi-reference configuration interaction(MRCI)approach and Davidson corrections(MRCI+Q).The AWCV5 Z basis set is employed in the calculations.The transition dipole moments(TDMs)of the A;Π■X^(1)Σ+transition are explored based on the AWCV5 Z basis set and(4,2,2,0)active space.The Schrödinger equation is solved via the LEVEL 8.2 program,and the vibrational levels and rotational constants of the X^(1)Σ+and A1Πstates are calculated.It is shown that the Al F molecule has high diagonal Franck-Condon factors(f00=0.9949 and f11=0.9854)and large Einstein coefficients for the transition of A;Π(ν′=0)■X^(1)Σ+(ν′′=0).In addition,the radiative lifetimes of the vibrational levels are close to 10-9 s for the A;Πstate.The line intensities of the A;Π(ν′=4-15)■X^(1)Σ+(ν′′=0)transitions are also calculated.The calculated TDMs and transition probabilities in this work are credible and provide some guidance for the study of similar transitions,particularly for exploring interstellar space.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11274097 and 61275132)the Natural Science Foundation of Henan Province,China(Grant No.2008A140008)
文摘The high level quantum chemistry ab inito multi-reference configuration interaction (MRCI) method with large V5Z basis set is used to calculate the spectroscopic properties of the 15 A-S electronic states (X1∑+, A I П, 1 △, 1 ∑, 3∑+, 3П, 3△, 3△ , 5∑+, 5П, 5△, 1П (II), ofAsO+ radical correlated to the dissociation limit As+(3pg) + O(3pg) and As+(IDg) + O(1Dg). In order to obtain better potential curves and more accurate spectroscopic properties, the Davidson modification is taken into account. With the potential energy curves (PECs) determined here, vibrational levels G(v) and inertial rotation constants Bu are computed for all the bound electronic states when the rotational quantum number J equals zero (J = 0). Except for the states X1∑+, A1П , it is the first time that the multi-reference configuration calculation has been used on the 13 A-S electronic states of the AsO+ radical. The potential energy curves of all the A-S electronic states are depicted according to the avoided crossing rule of the same symmetry. Spin-orbit coupling effect (SOC) is introduced into the states X1 ∑+, A1 П, 3П to consider its effects on the spectroscopic properties. Transition dipole moments (TDMs) from A1П 1, 3 П1 states to the ground state X1∑0+ are predicted as well.
基金Project supported by the National Natural Science Foundation of China(Grant No.61705182)
文摘The feasibility of laser cooling a CH molecule is investigated theoretically by employing the ab initio method. The potential energy curves for the five ∧-S states and eight Ω states of CH are determined by the multi-reference configuration interaction with the Davidson corrections(MRCI+Q) level of theory. The results agree well with the available experimental data and other theoretical values. Also, the permanent dipole moments and transition dipole moments of the CH molecule are calculated at the multi-reference configuration interaction(MRCI) level. We find highly diagonally distributed FranckCondon factors(f00 = 0.9950 and 0.9998) and branching ratios(R00 = 0.983 and 0.993) for the A^2△→ X2Π and C^2∑^+→X^2Π transitions. Moreover, the values of suitable radiative lifetime τ of the A2 A and C^2∑^+ states are evaluated to be9.64×10^-7 s and 2.02×10^-7 s, respectively, for rapid laser cooling. A scheme for laser cooling the CH molecule is designed. In the proposed cooling scheme, three wavelengths for A^2△→X^2Π and C^2∑^+→X^2Π transitions are used, and the main pump lasers are λ00=430.86 nm and 313.45 nm, respectively. The feasibility of laser cooling the CH molecules is demonstrated for each of these schemes, and this study offers a theoretical basis for experimental research into preparation of cold CH molecules.
文摘Potential energy curves (PECs) for the ground state (X2∑+) and the four excited electronic states (A2∏, B2∏, C2∑+, 4∏) of a Bell molecule are calculated using the multi-configuration reference single and double excited configuration interaction (MRCI) approach in combination with the aug-cc-pVTZ basis sets. The calculation covers the internuclear distance ranging from 0.07 nm to 0.70 nm, and the equilibrium bond length Re and the vertical excited energy Te are determined directly. It is evident that the X2∑+, A2∏, B2∏, C2∑+ states are bound and 4∏ is a repulsive excited state. With the potentials, all of the vibrational levels and inertial rotation constants are predicted when the rotational quantum number J is set to be equal to zero (J = 0) by numerically solving the radial SchrSdinger equation of nuclear motion. Then the spectroscopic data are obtained including the rotation coupling constant w e, the anharmonic constant WeXe, the equilibrium rotation constant Be, and the vibration-rotation coupling constant ae. These values are compared with the theoretical and experimental results currently available, showing that they are in agreement with each other.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11104217 and 11402199)the Program for New Scientific and Technological Star of Shaanxi Province,China(Grant No.2012KJXX-39)
文摘The feasibility of spin-forbidden cooling of the In H molecule is investigated based on ab initio quantum chemistry calculations. The potential energy curves for the X^1Σ0^+^+, a^3Π0-, a^3Π0^+, a^3Π1, a-3Π2, A-1Π1, 1-3Σ^0^-+, and 1-3Σ1-+states of In H are obtained based on multi-reference configuration interaction plus the Davidson corrections method. The calculated spectroscopic constants are in good agreement with the available experimental data. In addition, the influences of the active space and spin–orbit coupling effects on the potential energy curves and spectroscopic constants are also studied. For Re of a^3Π0^-, a^3Π0^+, a^3Π1, and a-3Π2 states, the error from large active space is small. The potential energy curve of the A-1Π1state is not smooth for small active space. The spin–orbit coupling effects have great influences on the potential well depth and equilibrium internuclear distance of the A-1Π state. The Franck–Condon factors and radiative lifetimes are obtained on the basis of the transition dipole moments of the a^3Π0^+)→ X^1Σ0^+^+, a-3Π1 → X-1Σ0^+-+, and A-1Π1 → X-1Σ0^+^+ transitions. Our calculation indicates that the a^3Π1( ν'= 0) → X-1Σ0^+^+(ν = 0) transition provides a highly diagonally distributed Franck–Condon factor and a short radiative lifetime for the a3Π1 state, which can ensure rapid and efficient laser cooling of In H.The proposed laser drives a-3Π1 → X-1Σ0^+^+ transitions by using three wavelengths.
基金Project supported by the National Magnetic Confinement Fusion Science Program of China (Grant No. 2010GB104003)the Fundamental Research Funds for the Central Universities,China (Grant No. 450060481375)
文摘The potential energy curves for neutrals and multiply charged ions of carbon monosulfide are computed with highly correlated multi-reference configuration interaction wavefunctions.The correlations of inner-shell electrons with the scalar relativistic effects are included in the present computations.The spectroscopic constants,dissociation energies,ionization energies for ground and low-lying excited states together with corresponding electronic configurations of ions are obtained,and a good agreement between the present work and existing experiments is found.No theoretical evidence is found for the adiabatically stable CSq+(q〉2) ions according to the present ab initio calculations.The calculated values for 1st-6th ionization energies are 11.25,32.66,64.82,106.25,159.75,and 224.64 eV,respectively.The kinetic energy release data of fragments are provided by the present work for further experimental comparisons.
文摘The potential energy curves (PECs) of the16 lowest electronic states in the representation <sup>2s+1</sup>Λ<sup> (+/-)</sup> of the molecule ScTe have been investigated via ab initio CASSCF and MRCI (single and double excitations with Davidson correction) calculations. The permanent dipole moment curves (PDMCs) and the spectroscopic constants such as vibrational harmonic frequency ω<sub>e</sub>, the internuclear distance at equilibrium R<sub>e</sub>, the rotational constant B<sub>e</sub>, and the electronic transition energy T<sub>e</sub> with respect to the ground state have been calculated for the different bound investigated electronic states. The comparison of the present results with the rare available theoretical data in literature shows an overall good agreement. To the best of our knowledge, 15 electronic states of the ScTe molecule are not yet investigated either experimentally or theoretically, they are investigated in the present work for the first time.