1
|
Steely A, Myers RL, Kortyna A, Huennekens J, Malenda RF, Faust C. Fitting an experimental potential energy curve for the 10(0 +)[43Π0] electronic state of NaCs. J Chem Phys 2019; 151:024307. [DOI: 10.1063/1.5100748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Andrew Steely
- Department of Physics, Susquehanna University, 514 University Ave., Selinsgrove, Pennsylvania 17870, USA
| | - Rachel L. Myers
- Department of Physics and Earth Science, Moravian College, 1200 Main St., Bethlehem, Pennsylvania 18018, USA
| | - Andrew Kortyna
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309, USA
| | - John Huennekens
- Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, Pennsylvania 18015, USA
| | - R. F. Malenda
- Department of Physics and Earth Science, Moravian College, 1200 Main St., Bethlehem, Pennsylvania 18018, USA
| | - Carl Faust
- Department of Physics, Susquehanna University, 514 University Ave., Selinsgrove, Pennsylvania 17870, USA
| |
Collapse
|
2
|
Faust C, Jones J, Huennekens J, Field RW. Experimental studies of the NaCs 12(0 +) [7 1Σ +] state: Spin-orbit and non-adiabatic interactions and quantum interference in the 12(0 +) [7 1Σ +] and 11(0 +) [5 3Π 0] emission spectra. J Chem Phys 2017; 146:104302. [PMID: 28298109 DOI: 10.1063/1.4976630] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
We present results from experimental studies of the 11(0+) and 12(0+) electronic states of the NaCs molecule. An optical-optical double resonance method is used to obtain Doppler-free excitation spectra. Selected data from the 11(0+) and 12(0+) high-lying electronic states are used to obtain Rydberg-Klein-Rees and Inverse Perturbation Approach potential energy curves. Interactions between these two electronic states are evident in the patterns observed in the bound-bound and bound-free fluorescence spectra. A model, based on two separate interaction mechanisms, is presented to describe how the wavefunctions of the two states mix. The electronic parts of the wavefunctions interact via spin-orbit coupling, while the individual rotation-vibration levels interact via a second mechanism, which is likely to be non-adiabatic coupling. A modified version of the BCONT program was used to simulate resolved fluorescence from both upper states. Parameters of the model that describe the two interaction mechanisms were varied until simulations were able to adequately reproduce experimental spectra.
Collapse
Affiliation(s)
- C Faust
- Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, Pennsylvania 18015, USA
| | - J Jones
- Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, Pennsylvania 18015, USA
| | - J Huennekens
- Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, Pennsylvania 18015, USADepartment of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - R W Field
- Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, Pennsylvania 18015, USADepartment of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| |
Collapse
|
3
|
Ashman S, McGeehan B, Wolfe CM, Faust C, Richter K, Jones J, Hickman AP, Huennekens J. Experimental studies of the NaCs 5(3)Π0 and 1(a)3Σ+ states. J Chem Phys 2012; 136:114313. [PMID: 22443770 DOI: 10.1063/1.3689388] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report high resolution measurements of 372 NaCs 5(3)Π(0)(v, J) ro-vibrational level energies in the range 0 ≤ v ≤ 22. The data have been used to construct NaCs 5(3)Π(0) potential energy curves using the Rydberg-Klein-Rees and inverted perturbation approximation methods. Bound-free 5(3)Π(0)(v, J) → 1(a)(3)Σ(+) emission has also been measured, and is used to determine the repulsive wall of the 1(a)(3)Σ(+) state and the 5(3)Π(0) → 1(a)(3)Σ(+) relative transition dipole moment function. Hyperfine structure in the 5(3)Π(0) state has not been observed in this experiment. This null result is explained using a simple vector coupling model.
Collapse
Affiliation(s)
- S Ashman
- Department of Physics, 16 Memorial Dr. East, Lehigh University, Bethlehem, Pennsylvania 18015, USA
| | | | | | | | | | | | | | | |
Collapse
|
4
|
Allouche AR, Aubert-Frécon M. Ab initio and long-range investigation of the Ω((+∕-)) states of NaK dissociating adiabatically up to Na(3s 2S(1/2)) + K(3d 2D(3/2)). J Chem Phys 2011; 135:024309. [PMID: 21766944 DOI: 10.1063/1.3607964] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
A theoretical investigation of the electronic structure of the NaK molecule including spin-orbit effects has been performed for the 34 Ω((+∕-)) states dissociating adiabatically into the limits up to Na(3s(2)S(1/2)) + K(3d(2)D(3/2)) from both an ab initio approach and a long-range model. Equilibrium distances, transition energies, harmonic frequencies as well as depths of wells and heights of humps are reported for all the states. Formulas for calculating the long-range energies for all the 0(+∕-), 1, 2, and 3 states under investigation are also displayed. They are expressed in terms of the C(n) (n = 6,8, ...) long-range coefficients and exchange integrals for the (2S+1)Λ((+)) parent states, available from literature. As present data could help experimentalists we make available extensive tables of energy values versus internuclear distances in our database at the web address: http://www-lasim.univ-lyon1.fr/spip.php?rubrique99.
Collapse
Affiliation(s)
- A R Allouche
- CNRS, UMR 5579, LASIM, Université de Lyon, F-69622 Lyon, France.
| | | |
Collapse
|
5
|
Miles RD, Morgus L, Kashinski DO, Huennekens J, Hickman AP. Nonadiabatic coupling in the 3 3Pi and 4 3Pi states of NaK. J Chem Phys 2006; 125:154304. [PMID: 17059252 DOI: 10.1063/1.2348635] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The excited 3 (3)Pi and 4 (3)Pi electronic states of the NaK molecule exhibit an avoided crossing, leading to the anomalous behavior of many features of the rovibrational energy levels belonging to each state. A joint experimental and theoretical investigation of these states has been carried out. Experimental measurements of the vibrational, rotational, and hyperfine structure of numerous levels of the 3 (3)Pi state were recently obtained using the Doppler-free, perturbation-facilitated optical-optical double resonance technique. Additional measurements for the 4 (3)Pi state as well as bound-free emission spectra from selected 3 (3)Pi, 4 (3)Pi, and mixed 3 (3)Pi to approximately 4 (3)Pi rovibrational levels are reported here. A model is also presented for calculating the mixed rovibrational level energies of the coupled 3 (3)Pi-4 (3)Pi system, starting from a 2x2 diabatic electronic Hamiltonian. The 3 (3)Pi and 4 (3)Pi potential curves and the coupling between them are simultaneously adjusted to fit the observed rovibrational levels of both states. The energy levels of the potential curves determined by the fit are in excellent agreement with experiment. The nonadiabatic coupling is sufficiently strong to cause an overall shift of 2-3 cm(-1) for many rovibrational levels as well as somewhat larger shifts for certain pairs of 3 (3)Pi to approximately 4 (3)Pi levels that would otherwise be very close together.
Collapse
Affiliation(s)
- R D Miles
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, USA
| | | | | | | | | |
Collapse
|
6
|
Lim IS, Lee WC, Lee YS, Jeung GH. Theoretical investigation of RbCs via two-component spin-orbit pseudopotentials: Spectroscopic constants and permanent dipole moment functions. J Chem Phys 2006; 124:234307. [PMID: 16821918 DOI: 10.1063/1.2204607] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Potential energy curves for the 28 lowest LambdaSigma states and 49 Omega states of RbCs are obtained from large-scale multireference configuration interaction calculations using both spin-averaged and two-component spin-orbit energy-consistent effective core potentials. Spectroscopic properties of all states are compared across available data in literature to date. Variations of the permanent dipole moments on the internuclear separation (R) for the (1)Sigma(+), (3)Sigma(+), (1)Pi, and (3)Pi states are evaluated over a wide range of R. The most important effects of the spin-orbit interaction on the dipole moment distribution are discussed.
Collapse
Affiliation(s)
- Ivan S Lim
- Quantum and Computational Chemistry Lab, Department of Chemistry, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejoen 305-701, Korea
| | | | | | | |
Collapse
|
7
|
Qi P, Lazarov G, Lyyra AM, Liu Y, Cui C, Li L, Jeung GH. The Na2 2 3pi(g) state: new observations and hyperfine structure. J Chem Phys 2006; 124:184304. [PMID: 16709103 DOI: 10.1063/1.2190217] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Many more Na2 2 3pi(g) v = 0-43, omega = 0, 1, 2 levels have been observed by sub-Doppler continuous wave perturbation facilitated optical-optical double resonance fluorescence excitation spectroscopy and the hyperfine structure of the omega = 0 and 2 levels has been resolved. New molecular constants for the less perturbed v = 0-43 levels have been obtained with these new and the previously reported data. The hyperfine coupling scheme of the observed 2 3pi(g) levels is close to Hund's case a(beta) with a Fermi contact constant b(F) = 160+/-5 MHz, which is smaller than the Fermi contact constants of other Na2 triplet Rydberg states, b(F) = 200-245 MHz.
Collapse
Affiliation(s)
- Peng Qi
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | | | | | | | | | | | | |
Collapse
|
8
|
Wilkins AD, Morgus L, Hernandez-Guzman J, Huennekens J, Hickman AP. The NaK 1 1,3delta states: theoretical and experimental studies of fine and hyperfine structure of rovibrational levels near the dissociation limit. J Chem Phys 2005; 123:124306. [PMID: 16392481 DOI: 10.1063/1.2010471] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Earlier high-resolution spectroscopic studies of the fine and hyperfine structure of rovibrational levels of the 1 3delta state of NaK have been extended to include high lying rovibrational levels with v < or = 59, of which the highest levels lie within approximately 4 cm(-1) of the dissociation limit. A potential curve is determined using the inverted perturbation approximation method that reproduces these levels to an accuracy of approximately 0.026 cm(-1). For the largest values of v, the outer turning points occur near R approximately 12.7 angstroms, which is sufficiently large to permit the estimation of the C6 coefficient for this state. The fine and hyperfine structure of the 1 3delta rovibrational levels has been fit using the matrix diagonalization method that has been applied to other states of NaK, leading to values of the spin-orbit coupling constant A(v) and the Fermi contact constant b(F). New values determined for v < or = 33 are consistent with values determined by a simpler method and reported earlier. The measured fine and hyperfine structure for v in the range 44 < or = v < or = 49 exhibits anomalous behavior whose origin is believed to be the mixing between the 1 3delta and 1 1delta states. The matrix diagonalization method has been extended to treat this interaction, and the results provide an accurate representation of the complicated patterns that arise. The analysis leads to accurate values for A(v) and b(F) for all values of v < or = 49. For higher v (50 < or = v < or = 59), several rovibrational levels have been assigned, but the pattern of fine and hyperfine structure is difficult to interpret. Some of the observed features may arise from effects not included in the current model.
Collapse
Affiliation(s)
- A D Wilkins
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, USA
| | | | | | | | | |
Collapse
|