- Email: [email protected]
2-X̃2Σ+ system of YbOH: Revised estimates of the ground state spin-rotation splitting parameters
Journal Pre-proofs Re-analysis of the 000 – 000 and 000 – 100 bands in the A2
1/2
- X 2+ system of
YbOH: revised estimates of the ground state spin-rotation splitting parameters J.A. Coxon, C. Linton PII: DOI: Reference:
S0022-2852(19)30295-4 https://doi.org/10.1016/j.jms.2019.111242 YJMSP 111242
To appear in:
Journal of Molecular Spectroscopy
Received Date: Revised Date: Accepted Date:
23 October 2019 12 December 2019 16 December 2019
Please cite this article as: J.A. Coxon, C. Linton, Re-analysis of the 000 – 000 and 000 – 100 bands in the A2
1/2
- X 2+ system of YbOH: revised estimates of the ground state spin-rotation splitting parameters, Journal of
Molecular Spectroscopy (2019), doi: https://doi.org/10.1016/j.jms.2019.111242
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
© 2019 Published by Elsevier Inc.
Re-analysis of the 000 – 000 and 000 – 100 bands in the A 2 1/2 X 2 system of YbOH: revised estimates of the ground state spin-rotation splitting parameters J. A. Coxona and C. Lintonb* a
Department of Chemistry, Dalhousie University, Halifax NS B3H 4J3, Canada
bPhysics
Department and Centre for Laser Atomic and Molecular Sciences (CLAMS),
University of New Brunswick, 8 Bailey Drive, Fredericton, NB E3B 5A3, Canada
* Corresponding author: email [email protected]
1
Abstract In the first observed spectrum (Melville and Coxon, 2001) of the 000 – 000 band of the
A 2 1/2 X 2 transition of YbOH, spin-doublets were resolved only at high-N and yielded a ground state spin-rotation constant, γ, that differs in both sign and magnitude from that obtained from recent higher resolution low–N data (Steimle and co-workers, 2018 - 2019). This note reexamines the original 2001 data and shows that the discrepancy is resolved by rearrangement of the original Q11 and R12 branch and isotopologue assignments of the 000 – 000 origin band. Reanalysis of the 000 – 100 band results in a revised negative γ for the υ1 = 1 (Yb-O stretch) level of the X 2 state which is close to that obtained from the 2018 - 2019 data.
2
As part of the original investigation into the spectroscopy of gas phase YbOH using an oven source with laser excitation spectroscopy [1], the 000-000 and 000-100 bands of the
A 2 1/2 X 2 transition were recorded at high resolution. The quoted 0.03 cm-1 linewidths of the spectra were sufficiently narrow to allow observation and analysis of parts of the rotational structure in the 000-000 bands of 174YbOH and 172YbOH, and in the 000-100 band of 174YbOH. The analysis produced X 2 state spin-rotation constants (γ) of +9.64(14) 10-4 cm-1 and +10.01(19) 10-4 cm-1 for the υ1 = 0 levels of 174YbOH and 172YbOH, and -1.62(48) 10-4 cm-1 for the υ1 = 1 level of 174YbOH. The γ-value for the X 2 υ1 = 0 level was obtained only from the resolved separation of the Q11(N) and R12(N) lines from N = 30 -78 (see fig. 4 of Ref. [1]). There were no spin-rotation data at lower N-values; nor was there any observation of the P11 + Q12 branches, which would also show the spin-rotation splitting, as they all lie in a highly congested region of the spectrum, and are not resolved. Recent experiments using the Arizona State University laser ablation source have subsequently produced higher resolution spectra of the 000-000 band with a linewidth of ~0.001 cm-1 [2]. Rotational structure in the congested low-N region of the spectrum is resolved. Examination of the spectrum, and the effect of an applied magnetic field, enabled positive identification of the spin-rotation doublets in both the Q11 + R12 and P11 + Q12 branches from N = 1 - 11. The assignments were confirmed by showing that they all satisfied the combination relation R11(N - 1) – Q12(N + 1) = Q11(N - 1) – P12(N + 1)
(1)
and the spin-rotation splitting was the same in the (Q11+R12) and (P11+Q12) branches P11(N) – Q12(N) = Q11(N) – R12(N) 3
(2)
The analysis produced a negative spin-rotation constant, γ ~ -2.7 10-3 cm-1. Analysis of subsequent Pump/Probe Microwave Optical Double Resonance (PPMODR) experiments, using some of the assigned low-N lines (N = 3 – 7) in [2], provided accurate frequencies (linewidth ~115 kHz) of pure rotational transitions in the X 2 state of 174YbOH with γ = -2.7069(19) 10-3 cm-1 [3]. This is about three times the value obtained in [1] and of opposite sign. There is a large gap in the range covered by the data in [2, 3] with N ≤ 12 and that in [1] with N ≥ 30. There appears to be a complete disconnect between the two data sets which warrants a re-examination of the data in [1]. Because there were spin-rotation splitting data in [1] only for the Q11 + R12, and none for the P11 + Q12 branches, there was insufficient information to use eq. (1) or (2) to assign definitively the two components of the spin-rotation doublets. Fig. 4 of [1] shows four rotational transitions ( N = 53 -56) in the Q11 + R12 branches. There are 4 main lines in each transition involving the two spin-rotation components in each of the 174YbOH and 172YbOH isotopologues. It was stated that, for each isotopologue, “the branches are assigned with the Q11 line at lower frequency and the R12 line at higher frequency” [1], which places the F1 component above F2, and gives a positive value for γ. This choice is arbitrary and was made because γ was expected to be positive [1]. The alternative assignment with the Q11 line at higher frequency, giving a negative γ, would be equally valid. Although refitting the data in [1] with the two branches interchanged gives an equally good fit with a negative γ, the large discrepancy in the magnitude of γ still remains. The two lower frequency lines in each rotational transition had been assigned to 174YbOH and the two higher frequency lines to 172YbOH [1]. This gave a very good fit to the data, but there are alternative assignments that would be equally valid. If the assignments of the second and third 4
lines are interchanged, the first and third lines would be the two components of 174YbOH, with the second and fourth lines the analogous components of
172YbOH.
This would increase the
magnitude of the spin-rotation splitting and decrease the shift between the two isotopologues. Thus we propose that the Q11 and R12 branches of the two isotopologues be re-labelled (in order of increasing frequency) as in Table 1, which lists the old and proposed new branch and isotopologue assignments. The R11 and P12 branches remain unchanged. A least-squares fit to the data in [1] for each isotopologue, using the new branch and isotope assignments, gave the same standard deviation as the original fits, but with γ = -0.002665(41) for
174YbOH
and γ = -
0.002686(21) cm-1 for 172YbOH. The 174YbOH value compares well with the double resonance value of γ = -0.0027069 cm-1 [3]. The full set of constants and the standard deviation of the fits are listed in Table 2 and the complete line lists are provided in the supplementary data. The spin-rotation distortion constant for
174YbOH,
γD = 1.77(9) 10-7 cm-1, is in good
agreement with the PPMODR value of 1.59(19) 10-7 cm-1 [3]. As the PPMODR data covered only N = 3 – 7, γD would have only a small effect and it would not be expected to be valid in the N = 41 – 78 range covered by the present data. Fig. 1 shows a plot of the observed spin-rotation splittings against N for the PPMODR (black squares) and present (red circles) data. The dashed (black) line, which shows the calculated splitting using the PPMODR values of γ and γD, does not reproduce the present high-N splittings as well as the solid (red) line, which uses γ from the PPMODR data and the present value of γD. In our fit to the
172YbOH
data, γD was not well
determined; thus it was fixed at the 174YbOH value. Further evidence for the new assignments is obtained from the isotope effect. The branch reassignment reduces the separation between the
172YbOH
and
174YbOH
lines. The ratio of
rotational constants B(172 YbOH)/B(174 YbOH) = 1.00252 for the original assignments [1] and
5
1.00106 for the new assignments. The corresponding ratios for the upper state are 1.00252 [1] and 1.00109. The ratios with the new assignments are in excellent agreement with the theoretical value of 1.00103 calculated from the moments of inertia. For the much weaker 000 – 100 band, only the R11 and P12 branches could be assigned and, as there were no measurements of P11 + Q12 and Q11 + R12 branches, there was therefore no direct measurement of the spin-rotation splitting [1]. However, as the observed branches sampled different ground state spin components, and the upper 000 state was common to both transitions, the upper state energies could be determined accurately by fixing the constants to those obtained from the 000 – 000 band. The lower state energies of the two spin components were then determined from the line frequencies. With the same assignments as in [1], these data sample both lower state spin components for only a small rotational range, N″ = 20 – 32. It was not surprising, then, that the value of γD obtained in a preliminary fit was not determined significantly. The final fit in Table 2 with γD fixed at zero gives γ = -0.00364(5) cm-1 for the vibrationally excited 100 level of the ground state. This is in excellent agreement with the γ = -0.00369 cm-1 value obtained from a fit, which also did not include γD, to the recent higher resolution measurements of the low-N″ transitions (N″ ≤ 8) [2]. The ~20 times increase in magnitude over the previous estimate of -0.000162(48) cm-1 [1] is due to the change in the upper state constants that result from the new assignments in the origin band. Conclusions: Re-arrangement of the original Q11 and R12 branch and isotopologue assignments [1] of the 000 – 000 origin band of the A 2 1/2 X 2 system of YbOH has resolved the discrepancy between the positive value of the ground state spin-rotation constant γ obtained from the high-N (N ≥ 30) rotational data in [1] and the larger negative value obtained from the more precise low6
N data (N ≤ 7) in the recent higher resolution PPMODR experiment [3]. Subsequent re-analysis of the 000 – 100 band [1] resulted in a revised value of γ, also negative, for the υ1 = 1 level of the
X 2 state which is close to that obtained from the higher resolution data [2]. While a negative value of γ in the ground state levels was unexpected, the same was observed in the iso-electronic molecule YbF [4], and possible reasons for this have been discussed in the previous articles [1, 3]. The molecular parameters in Table 2 are presented simply to show that agreement with those obtained in [2] and [3] demonstrates the validity of the present re-assignment of the data in [1]. The parameters presented in [2], obtained from a fit to optical spectroscopic data in a molecular beam sample, as well as the standard deviation of the fit, are approximately an order of magnitude more precise than those in Table 2 and should be used whenever there is a need for precise calculations or predictions of YbOH ground or excited state energies. It is hoped that future higher resolution experiments may resolve the splitting in the (P11 + Q12) and (Q11 + R12) branches in transitions involving excited vibrational modes of the ground state and allow unambiguous determination of γ for vibrationally excited levels. Acknowledgment The experiment [1] on which this re-analysis is based was funded by a grant from the Natural Sciences and Engineering Research Council (NSERC) of Canada.
7
References: 1. T. C. Melville and J. A. Coxon, J. Chem. Phys, 115 (2001) 6974 – 6978. 2. T. C. Steimle, C. Linton, E. T. Mengesha, X. Bai and A. T. Le, Phys. Rev. A, 100 (2019) 052509 3. S. Nakhate, T. C. Steimle, N. H. Pilgram and N. R. Hutzler, Chem. Phys. Lett. 715 (2019) 105 – 108. 4. C.S. Dickinson, J.A. Coxon, N.R. Walker and M.C.L. Gerry, J. Chem. Phys. 115 (2001) 69796989.
8
Figure caption Fig 1: Plot of spin-rotation splitting in the X 2 state against N for the low-N data [3] (black squares) and the present high-N data (red circles). The calculated values with (i) γ and γD from [3] (dotted (black) line) and (ii) γ from [3] and γD from the present work (solid (red) line) are also shown.
9
Old [1]
New
174YbOH
Q11(J)
174YbOH
174YbOH
R12(J)
172YbOH
R12(J)
172YbOH
Q11(J)
174YbOH
Q11(J)
172YbOH
R12(J)
172YbOH
10
R12(J - 1)
Q11(J + 1)
Table 1: Old [1] and New Isotopologue and Q11 and R12 Branch Assignments in the A 2 1/2 X 2 000-000 Band of YbOH
11
PPMODR[3]
X 2
A 2 1/2
(000-000)
(000-100)
Parameter
174YbOH
174YbOH
172YbOH
174YbOH
T0″
0
0
0
529.3410(15)
B″
0.245116257(10)
0.245165(13)
0.245424(20)
0.243709(4)
107D″
2.029(13)
2.157(27)
2.204(42)
2.157(20)
″
-0.0027069(19)
-0.002665(41)
107D″
1.59(19)
1.77(9)
A′
[1350]b
B′
0.253089(13)
-0.002686(21) [1.77]a [1350]b 0.253365(19)
-0.003644(50) [0.0] [1350]b [0.253089]c
107D′
2.292(26)
2.348(39)
[2.292]c
p+2q′
-0.436917(63)
-0.437285(89)
[-0.436917]c
106(p+2q)D′
2.410(20)
2.380(28)
[2.410]c
T0
17998.6191(6)
17998.6312(10)
[17998.6191]c
d
0.0033
0.0048
0.0034
value for 174YbOH. b fixed c Constants fixed at values obtained from the 000 – 000 band d σ denotes the estimated standard errors for the fitted line positions of each band.
12
Table 2: Molecular Constants (cm-1) of the X 2 (000, 100) and A 2 1/2
(000) levels of YbOH a
γD for 172YbOH is fixed at the fitted
Conflict of interest: There is no conflict of interest or competing interests associated with this research
13
Author statement: Both authors contributed equally to all aspects of the research described in this communication and in its preparation.
14
Highlights:
1. Large discrepancy between 2001 [1] and 2018-19 [2,3] spin-rotation constant γ.
2. Rearranged the branch and isotopologue assignments in the 2001 data [1].
3. Revised assignments give γ in good agreement with 2018-2019 values [2,3]
15
GA
16
1/2
- X 2+ system of
YbOH: revised estimates of the ground state spin-rotation splitting parameters J.A. Coxon, C. Linton PII: DOI: Reference:
S0022-2852(19)30295-4 https://doi.org/10.1016/j.jms.2019.111242 YJMSP 111242
To appear in:
Journal of Molecular Spectroscopy
Received Date: Revised Date: Accepted Date:
23 October 2019 12 December 2019 16 December 2019
Please cite this article as: J.A. Coxon, C. Linton, Re-analysis of the 000 – 000 and 000 – 100 bands in the A2
1/2
- X 2+ system of YbOH: revised estimates of the ground state spin-rotation splitting parameters, Journal of
Molecular Spectroscopy (2019), doi: https://doi.org/10.1016/j.jms.2019.111242
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
© 2019 Published by Elsevier Inc.
Re-analysis of the 000 – 000 and 000 – 100 bands in the A 2 1/2 X 2 system of YbOH: revised estimates of the ground state spin-rotation splitting parameters J. A. Coxona and C. Lintonb* a
Department of Chemistry, Dalhousie University, Halifax NS B3H 4J3, Canada
bPhysics
Department and Centre for Laser Atomic and Molecular Sciences (CLAMS),
University of New Brunswick, 8 Bailey Drive, Fredericton, NB E3B 5A3, Canada
* Corresponding author: email [email protected]
1
Abstract In the first observed spectrum (Melville and Coxon, 2001) of the 000 – 000 band of the
A 2 1/2 X 2 transition of YbOH, spin-doublets were resolved only at high-N and yielded a ground state spin-rotation constant, γ, that differs in both sign and magnitude from that obtained from recent higher resolution low–N data (Steimle and co-workers, 2018 - 2019). This note reexamines the original 2001 data and shows that the discrepancy is resolved by rearrangement of the original Q11 and R12 branch and isotopologue assignments of the 000 – 000 origin band. Reanalysis of the 000 – 100 band results in a revised negative γ for the υ1 = 1 (Yb-O stretch) level of the X 2 state which is close to that obtained from the 2018 - 2019 data.
2
As part of the original investigation into the spectroscopy of gas phase YbOH using an oven source with laser excitation spectroscopy [1], the 000-000 and 000-100 bands of the
A 2 1/2 X 2 transition were recorded at high resolution. The quoted 0.03 cm-1 linewidths of the spectra were sufficiently narrow to allow observation and analysis of parts of the rotational structure in the 000-000 bands of 174YbOH and 172YbOH, and in the 000-100 band of 174YbOH. The analysis produced X 2 state spin-rotation constants (γ) of +9.64(14) 10-4 cm-1 and +10.01(19) 10-4 cm-1 for the υ1 = 0 levels of 174YbOH and 172YbOH, and -1.62(48) 10-4 cm-1 for the υ1 = 1 level of 174YbOH. The γ-value for the X 2 υ1 = 0 level was obtained only from the resolved separation of the Q11(N) and R12(N) lines from N = 30 -78 (see fig. 4 of Ref. [1]). There were no spin-rotation data at lower N-values; nor was there any observation of the P11 + Q12 branches, which would also show the spin-rotation splitting, as they all lie in a highly congested region of the spectrum, and are not resolved. Recent experiments using the Arizona State University laser ablation source have subsequently produced higher resolution spectra of the 000-000 band with a linewidth of ~0.001 cm-1 [2]. Rotational structure in the congested low-N region of the spectrum is resolved. Examination of the spectrum, and the effect of an applied magnetic field, enabled positive identification of the spin-rotation doublets in both the Q11 + R12 and P11 + Q12 branches from N = 1 - 11. The assignments were confirmed by showing that they all satisfied the combination relation R11(N - 1) – Q12(N + 1) = Q11(N - 1) – P12(N + 1)
(1)
and the spin-rotation splitting was the same in the (Q11+R12) and (P11+Q12) branches P11(N) – Q12(N) = Q11(N) – R12(N) 3
(2)
The analysis produced a negative spin-rotation constant, γ ~ -2.7 10-3 cm-1. Analysis of subsequent Pump/Probe Microwave Optical Double Resonance (PPMODR) experiments, using some of the assigned low-N lines (N = 3 – 7) in [2], provided accurate frequencies (linewidth ~115 kHz) of pure rotational transitions in the X 2 state of 174YbOH with γ = -2.7069(19) 10-3 cm-1 [3]. This is about three times the value obtained in [1] and of opposite sign. There is a large gap in the range covered by the data in [2, 3] with N ≤ 12 and that in [1] with N ≥ 30. There appears to be a complete disconnect between the two data sets which warrants a re-examination of the data in [1]. Because there were spin-rotation splitting data in [1] only for the Q11 + R12, and none for the P11 + Q12 branches, there was insufficient information to use eq. (1) or (2) to assign definitively the two components of the spin-rotation doublets. Fig. 4 of [1] shows four rotational transitions ( N = 53 -56) in the Q11 + R12 branches. There are 4 main lines in each transition involving the two spin-rotation components in each of the 174YbOH and 172YbOH isotopologues. It was stated that, for each isotopologue, “the branches are assigned with the Q11 line at lower frequency and the R12 line at higher frequency” [1], which places the F1 component above F2, and gives a positive value for γ. This choice is arbitrary and was made because γ was expected to be positive [1]. The alternative assignment with the Q11 line at higher frequency, giving a negative γ, would be equally valid. Although refitting the data in [1] with the two branches interchanged gives an equally good fit with a negative γ, the large discrepancy in the magnitude of γ still remains. The two lower frequency lines in each rotational transition had been assigned to 174YbOH and the two higher frequency lines to 172YbOH [1]. This gave a very good fit to the data, but there are alternative assignments that would be equally valid. If the assignments of the second and third 4
lines are interchanged, the first and third lines would be the two components of 174YbOH, with the second and fourth lines the analogous components of
172YbOH.
This would increase the
magnitude of the spin-rotation splitting and decrease the shift between the two isotopologues. Thus we propose that the Q11 and R12 branches of the two isotopologues be re-labelled (in order of increasing frequency) as in Table 1, which lists the old and proposed new branch and isotopologue assignments. The R11 and P12 branches remain unchanged. A least-squares fit to the data in [1] for each isotopologue, using the new branch and isotope assignments, gave the same standard deviation as the original fits, but with γ = -0.002665(41) for
174YbOH
and γ = -
0.002686(21) cm-1 for 172YbOH. The 174YbOH value compares well with the double resonance value of γ = -0.0027069 cm-1 [3]. The full set of constants and the standard deviation of the fits are listed in Table 2 and the complete line lists are provided in the supplementary data. The spin-rotation distortion constant for
174YbOH,
γD = 1.77(9) 10-7 cm-1, is in good
agreement with the PPMODR value of 1.59(19) 10-7 cm-1 [3]. As the PPMODR data covered only N = 3 – 7, γD would have only a small effect and it would not be expected to be valid in the N = 41 – 78 range covered by the present data. Fig. 1 shows a plot of the observed spin-rotation splittings against N for the PPMODR (black squares) and present (red circles) data. The dashed (black) line, which shows the calculated splitting using the PPMODR values of γ and γD, does not reproduce the present high-N splittings as well as the solid (red) line, which uses γ from the PPMODR data and the present value of γD. In our fit to the
172YbOH
data, γD was not well
determined; thus it was fixed at the 174YbOH value. Further evidence for the new assignments is obtained from the isotope effect. The branch reassignment reduces the separation between the
172YbOH
and
174YbOH
lines. The ratio of
rotational constants B(172 YbOH)/B(174 YbOH) = 1.00252 for the original assignments [1] and
5
1.00106 for the new assignments. The corresponding ratios for the upper state are 1.00252 [1] and 1.00109. The ratios with the new assignments are in excellent agreement with the theoretical value of 1.00103 calculated from the moments of inertia. For the much weaker 000 – 100 band, only the R11 and P12 branches could be assigned and, as there were no measurements of P11 + Q12 and Q11 + R12 branches, there was therefore no direct measurement of the spin-rotation splitting [1]. However, as the observed branches sampled different ground state spin components, and the upper 000 state was common to both transitions, the upper state energies could be determined accurately by fixing the constants to those obtained from the 000 – 000 band. The lower state energies of the two spin components were then determined from the line frequencies. With the same assignments as in [1], these data sample both lower state spin components for only a small rotational range, N″ = 20 – 32. It was not surprising, then, that the value of γD obtained in a preliminary fit was not determined significantly. The final fit in Table 2 with γD fixed at zero gives γ = -0.00364(5) cm-1 for the vibrationally excited 100 level of the ground state. This is in excellent agreement with the γ = -0.00369 cm-1 value obtained from a fit, which also did not include γD, to the recent higher resolution measurements of the low-N″ transitions (N″ ≤ 8) [2]. The ~20 times increase in magnitude over the previous estimate of -0.000162(48) cm-1 [1] is due to the change in the upper state constants that result from the new assignments in the origin band. Conclusions: Re-arrangement of the original Q11 and R12 branch and isotopologue assignments [1] of the 000 – 000 origin band of the A 2 1/2 X 2 system of YbOH has resolved the discrepancy between the positive value of the ground state spin-rotation constant γ obtained from the high-N (N ≥ 30) rotational data in [1] and the larger negative value obtained from the more precise low6
N data (N ≤ 7) in the recent higher resolution PPMODR experiment [3]. Subsequent re-analysis of the 000 – 100 band [1] resulted in a revised value of γ, also negative, for the υ1 = 1 level of the
X 2 state which is close to that obtained from the higher resolution data [2]. While a negative value of γ in the ground state levels was unexpected, the same was observed in the iso-electronic molecule YbF [4], and possible reasons for this have been discussed in the previous articles [1, 3]. The molecular parameters in Table 2 are presented simply to show that agreement with those obtained in [2] and [3] demonstrates the validity of the present re-assignment of the data in [1]. The parameters presented in [2], obtained from a fit to optical spectroscopic data in a molecular beam sample, as well as the standard deviation of the fit, are approximately an order of magnitude more precise than those in Table 2 and should be used whenever there is a need for precise calculations or predictions of YbOH ground or excited state energies. It is hoped that future higher resolution experiments may resolve the splitting in the (P11 + Q12) and (Q11 + R12) branches in transitions involving excited vibrational modes of the ground state and allow unambiguous determination of γ for vibrationally excited levels. Acknowledgment The experiment [1] on which this re-analysis is based was funded by a grant from the Natural Sciences and Engineering Research Council (NSERC) of Canada.
7
References: 1. T. C. Melville and J. A. Coxon, J. Chem. Phys, 115 (2001) 6974 – 6978. 2. T. C. Steimle, C. Linton, E. T. Mengesha, X. Bai and A. T. Le, Phys. Rev. A, 100 (2019) 052509 3. S. Nakhate, T. C. Steimle, N. H. Pilgram and N. R. Hutzler, Chem. Phys. Lett. 715 (2019) 105 – 108. 4. C.S. Dickinson, J.A. Coxon, N.R. Walker and M.C.L. Gerry, J. Chem. Phys. 115 (2001) 69796989.
8
Figure caption Fig 1: Plot of spin-rotation splitting in the X 2 state against N for the low-N data [3] (black squares) and the present high-N data (red circles). The calculated values with (i) γ and γD from [3] (dotted (black) line) and (ii) γ from [3] and γD from the present work (solid (red) line) are also shown.
9
Old [1]
New
174YbOH
Q11(J)
174YbOH
174YbOH
R12(J)
172YbOH
R12(J)
172YbOH
Q11(J)
174YbOH
Q11(J)
172YbOH
R12(J)
172YbOH
10
R12(J - 1)
Q11(J + 1)
Table 1: Old [1] and New Isotopologue and Q11 and R12 Branch Assignments in the A 2 1/2 X 2 000-000 Band of YbOH
11
PPMODR[3]
X 2
A 2 1/2
(000-000)
(000-100)
Parameter
174YbOH
174YbOH
172YbOH
174YbOH
T0″
0
0
0
529.3410(15)
B″
0.245116257(10)
0.245165(13)
0.245424(20)
0.243709(4)
107D″
2.029(13)
2.157(27)
2.204(42)
2.157(20)
″
-0.0027069(19)
-0.002665(41)
107D″
1.59(19)
1.77(9)
A′
[1350]b
B′
0.253089(13)
-0.002686(21) [1.77]a [1350]b 0.253365(19)
-0.003644(50) [0.0] [1350]b [0.253089]c
107D′
2.292(26)
2.348(39)
[2.292]c
p+2q′
-0.436917(63)
-0.437285(89)
[-0.436917]c
106(p+2q)D′
2.410(20)
2.380(28)
[2.410]c
T0
17998.6191(6)
17998.6312(10)
[17998.6191]c
d
0.0033
0.0048
0.0034
value for 174YbOH. b fixed c Constants fixed at values obtained from the 000 – 000 band d σ denotes the estimated standard errors for the fitted line positions of each band.
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Table 2: Molecular Constants (cm-1) of the X 2 (000, 100) and A 2 1/2
(000) levels of YbOH a
γD for 172YbOH is fixed at the fitted
Conflict of interest: There is no conflict of interest or competing interests associated with this research
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Author statement: Both authors contributed equally to all aspects of the research described in this communication and in its preparation.
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Highlights:
1. Large discrepancy between 2001 [1] and 2018-19 [2,3] spin-rotation constant γ.
2. Rearranged the branch and isotopologue assignments in the 2001 data [1].
3. Revised assignments give γ in good agreement with 2018-2019 values [2,3]
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GA
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