Rotational constants and centrifugal distortion constants of a molecule are the essence of its rotational or rovibrational spectrum (e.g., from microwave, millimeter wave, and infrared experiments). These parameters condense the spectroscopic characteristics of a molecule and, thus, are a valuable resource in terms of presenting and communicating spectroscopic observations. While spectroscopic parameters are obtained from experimental spectra by fitting an effective rovibrational Hamiltonian to transition frequencies, the ab initio calculation of these parameters is usually done within vibrational perturbation theory. In the present work, we investigate an approach related to the experimental fitting procedure, but relying solely on ab initio data obtained from variational calculations, i.e., we perform a nonlinear least squares fit of Watson’s A- and S-reduced rotation–vibration Hamiltonian to rovibrational state energies (resp. transition frequencies) from rotational–vibrational configuration interaction calculations. We include up to sextic centrifugal distortion constants. By relying on an educated guess of spectroscopic parameters from vibrational configuration interaction and vibrational perturbation theory, the fitting procedure is very efficient. We observe excellent agreement with experimentally derived parameters.

1.
C.
Puzzarini
, “
Grand challenges in astrochemistry
,”
Front. Astron. Space Sci.
7
,
8
(
2020
).
2.
E.
Herbst
and
E. F.
Van Dishoeck
, “
Complex organic interstellar molecules
,”
Annu. Rev. Astron. Astrophys.
47
,
427
(
2009
).
3.
A. G. G. M.
Tielens
, “
Interstellar polycyclic aromatic hydrocarbon molecules
,”
Annu. Rev. Astron. Astrophys.
46
,
289
(
2008
).
4.
B. A.
McGuire
, “
2021 census of Interstellar, Circumstellar, Extragalactic
,”
Astrophys. J. Suppl. Ser.
259
,
30
(
2022
).
5.
S. L.
Widicus Weaver
, “
Millimeterwave and Submillimeterwave laboratory spectroscopy in support of observational astronomy
,”
Annu. Rev. Astron. Astrophys.
57
,
79
(
2019
).
6.
V. I.
Feldman
,
S. V.
Ryazantsev
, and
S. V.
Kameneva
, “
Matrix isolation in laboratory astrochemistry: state-of-the-art, implications and perspective
,”
Russ. Chem. Rev.
90
,
1142
(
2021
).
7.
R. C.
Fortenberry
, “
Quantum astrochemical spectroscopy
,”
Int. J. Quantum Chem.
117
,
81
(
2017
).
8.
M.
Biczysko
,
J.
Bloino
, and
C.
Puzzarini
, “
Computational challenges in astrochemistry
,”
Wiley Interdiscip. Rev.: Comput. Mol. Sci.
8
,
e1349
(
2018
).
9.
V.
Barone
,
S.
Alessandrini
,
M.
Biczysko
,
J. R.
Cheeseman
,
D. C.
Clary
,
A. B.
McCoy
,
R. J.
DiRisio
,
F.
Neese
,
M.
Melosso
, and
C.
Puzzarini
, “
Computational molecular spectroscopy
,”
Nat. Rev. Methods Primers
1
,
38
(
2021
).
10.
H. M.
Pickett
,
R. L.
Poynter
,
E. A.
Cohen
,
M. L.
Delitsky
,
J. C.
Pearson
, and
H. S. P.
Müller
, “
Submillimeter, millimeter, and microwave spectral line catalog
,”
J. Quant. Spectrosc. Radiat. Transfer
60
,
883
(
1998
).
11.
J.
Tennyson
and
S. N.
Yurchenko
, “
ExoMol: Molecular line lists for exoplanet and other atmospheres
,”
Mon. Not. R. Astron. Soc.
425
,
21
(
2012
).
12.
I. E.
Gordon
,
L. S.
Rothman
,
R. J.
Hargreaves
,
R.
Hashemi
,
E. V.
Karlovets
,
F. M.
Skinner
,
E. K.
Conway
,
C.
Hill
,
R. V.
Kochanov
,
Y.
Tan
,
P.
Wcisło
,
A. A.
Finenko
,
K.
Nelson
,
P. F.
Bernath
,
M.
Birk
,
V.
Boudon
,
A.
Campargue
,
K. V.
Chance
,
A.
Coustenis
,
B. J.
Drouin
,
J. M.
Flaud
,
R. R.
Gamache
,
J. T.
Hodges
,
D.
Jacquemart
,
E. J.
Mlawer
,
A. V.
Nikitin
,
V. I.
Perevalov
,
M.
Rotger
,
J.
Tennyson
,
G. C.
Toon
,
H.
Tran
,
V. G.
Tyuterev
,
E. M.
Adkins
,
A.
Baker
,
A.
Barbe
,
E.
Canè
,
A. G.
Császár
,
A.
Dudaryonok
,
O.
Egorov
,
A. J.
Fleisher
,
H.
Fleurbaey
,
A.
Foltynowicz
,
T.
Furtenbacher
,
J. J.
Harrison
,
J. M.
Hartmann
,
V. M.
Horneman
,
X.
Huang
,
T.
Karman
,
J.
Karns
,
S.
Kassi
,
I.
Kleiner
,
V.
Kofman
,
F.
Kwabia–Tchana
,
N. N.
Lavrentieva
,
T. J.
Lee
,
D. A.
Long
,
A. A.
Lukashevskaya
,
O. M.
Lyulin
,
V. Y.
Makhnev
,
W.
Matt
,
S. T.
Massie
,
M.
Melosso
,
S. N.
Mikhailenko
,
D.
Mondelain
,
H. S. P.
Müller
,
O. V.
Naumenko
,
A.
Perrin
,
O. L.
Polyansky
,
E.
Raddaoui
,
P. L.
Raston
,
Z. D.
Reed
,
M.
Rey
,
C.
Richard
,
R.
Tóbiás
,
I.
Sadiek
,
D. W.
Schwenke
,
E.
Starikova
,
K.
Sung
,
F.
Tamassia
,
S. A.
Tashkun
,
J.
Vander Auwera
,
I. A.
Vasilenko
,
A. A.
Vigasin
,
G. L.
Villanueva
,
B.
Vispoel
,
G.
Wagner
,
A.
Yachmenev
, and
S. N.
Yurchenko
, “
The HITRAN2020 molecular spectroscopic database
,”
J. Quant. Spectrosc. Radiat. Transfer
277
,
107949
(
2022
).
13.
J. K. G.
Watson
, “
Centrifugal corrections for asymmetric-top molecules
,”
J. Chem. Phys.
45
,
1360
(
1966
).
14.
J. K. G.
Watson
, “
Determination of centrifugal-distortion coefficients of asymmetric-top molecules
,”
J. Chem. Phys.
46
,
1935
(
1967
).
15.
J. K. G.
Watson
, “
Determination of centrifugal-distortion coefficients of asymmetric top molecules. II. Dreizler, Dendl, and Rudolph's results
,”
J. Chem. Phys.
48
,
181
(
1968
).
16.
J. K. G.
Watson
, “
Determination of centrifugal distortion coefficients of asymmetric top molecules. III. sextic coefficients
,”
J. Chem. Phys.
48
,
4517
(
1968
).
17.
J. K. G.
Watson
, “
Aspects of quartic and sextic centrifugaleffects on rotational energy levels
,”
Vibrational Spectra and Structure
(
Elsevier Ltd.
,
1977
), Vol. 6, pp.
1
80
.
18.
J. C.
Santos
,
A. B.
Rocha
, and
R. R.
Oliveira
, “
Rotational spectrum simulations of asymmetric tops in an astrochemical context
,”
J. Mol. Model.
26
,
1
16
(
2020
).
19.
R. C.
Fortenberry
and
T. J.
Lee
,
Annual Reports in Computational Chemistry
, 1st ed. (
Elsevier B.V.
,
2019
), Vol. 15, pp.
173
202
.
20.
C.
Puzzarini
and
V.
Barone
, “
The challenging playground of astrochemistry: An integrated rotational spectroscopy-quantum chemistry strategy
,”
Phys. Chem. Chem. Phys.
22
,
6507
(
2020
).
21.
M. B.
Gardner
,
B. R.
Westbrook
,
R. C.
Fortenberry
, and
T. J.
Lee
, “
Highly-accurate quartic force fields for the prediction of anharmonic rotational constants and fundamental vibrational frequencies
,”
Spectrochim. Acta, Part A
248
,
119184
(
2021
).
22.
J.
Tennyson
and
S. N.
Yurchenko
, “
The ExoMol project: Software for computing large molecular line lists
,”
Int. J. Quantum Chem.
117
,
92
(
2017
).
23.
X.
Huang
,
D. W.
Schwenke
, and
T. J.
Lee
, “
What it takes to compute highly accurate rovibrational line lists for use in astrochemistry
,”
Acc. Chem. Res.
54
,
1311
(
2021
).
24.
S.
Erfort
,
M.
Tschöpe
, and
G.
Rauhut
, “
Toward a fully automated calculation of rovibrational infrared intensities for semirigidpolyatomic molecules
,”
J. Chem. Phys.
152
,
244104
(
2020
).
25.
H. M.
Pickett
, “
The fitting and prediction of vibration-rotation spectra with spin interactions
,”
J. Mol. Spectrosc.
148
,
371
(
1991
).
26.
C. M.
Western
, “
PGOPHER: A program for simulating rotational, vibrational and electronic spectra
,”
J. Quant. Spectrosc. Radiat. Transfer
186
,
221
(
2017
).
27.
H.-J.
Werner
,
P. J.
Knowles
,
F. R.
Manby
,
J. A.
Black
,
K.
Doll
,
A.
Heßelmann
,
D.
Kats
,
A.
Köhn
,
T.
Korona
,
D. A.
Kreplin
,
Q.
Ma
,
T. F.
Miller
,
A.
Mitrushchenkov
,
K. A.
Peterson
,
I.
Polyak
,
G.
Rauhut
, and
M.
Sibaev
, “
The Molpro quantum chemistry package
,”
J. Chem. Phys.
152
,
144107
(
2020
).
28.
J. K. G.
Watson
, “
Simplification of molecular vibration-rotation hamiltonian
,”
Mol. Phys.
15
,
479
(
1968
).
29.
S.
Carter
,
S. J.
Culik
, and
J. M.
Bowman
, “
Vibrational selfconsistent field method for many-mode systems: A new approach and application to the vibrations of co adsorbed on Cu(100)
,”
J. Chem. Phys.
107
,
10458
(
1997
).
30.
J. M.
Bowman
,
T.
Carrington
, Jr.
, and
H.-D.
Meyer
, “
Variational quantum approaches for computing vibrational energies of polyatomic molecules
,”
Mol. Phys.
106
,
2145
(
2008
).
31.
M.
Neff
,
T.
Hrenar
,
D.
Oschetzki
, and
G.
Rauhut
, “
Convergence of vibrational angular momentum terms within theWatson Hamiltonian
,”
J. Chem. Phys.
134
,
064105
(
2011
).
32.
M.
Neff
and
G.
Rauhut
, “
Toward large scale vibrational configuration interaction calculations
,”
J. Chem. Phys.
131
,
124129
(
2009
).
33.
T.
Mathea
and
G.
Rauhut
, “
Advances in vibrational configuration interaction theory - part 1: Efficient calculation of vibrational angular momentum terms
,”
J. Comput. Chem.
42
,
2321
(
2021
).
34.
T.
Mathea
,
T.
Petrenko
, and
G.
Rauhut
, “
Advances in vibrational configuration interaction theory - part 2: Fast screening of the correlation space
,”
J. Comput. Chem.
43
,
6
(
2022
).
35.
B.
Schröder
and
G.
Rauhut
, “
Vibrational configuration interaction theory
,” in
Vibrational Dynamics of Molecules
, edited by
J. M.
Bowman
(
World Scientific
,
Singapore
,
2022
), pp.
1
40
.
36.
J. M.
Bowman
, “
The self-consistent-field approach to polyatomic vibrations
,”
Acc. Chem. Res.
19
,
202
(
1986
).
37.
D. A.
Jelski
,
R. H.
Haley
, and
J. M.
Bowman
, “
New vibrational self-consistent field program for large molecules
,”
J. Comput. Chem.
17
,
1645
(
1996
).
38.
G.
Rauhut
, “
Efficient calculation of potential energy surfaces for the generation of vibrational wave functions
,”
J. Chem. Phys.
121
,
9313
(
2004
).
39.
D.
Kivelson
and
E. B.
Wilson
, “
Approximate treatment of the effect of centrifugal distortion on the rotational energy levels of asymmetric-rotor molecules
,”
J. Chem. Phys.
20
,
1575
(
1952
).
40.
J. K. G.
Watson
,
Handbook of High-Resolution Spectroscopy
(
John Wiley & Sons
,
2011
), Chap. Indeterminacies of Fitting Parameters in Molecular Spectroscopy, pp.
587
605
.
41.
G.
Winnewisser
and
P.
Helminger
, “
Millimeter wave rotational spectrum of HSSH and DSSD. II. anomalous K doubling caused by centrifugal distortion in DSSD
,”
J. Chem. Phys.
56
,
2954
(
1972
).
42.
B. P.
van Eijck
, “
Reformulation of quartic centrifugal distortion hamiltonian
,”
J. Mol. Spectrosc.
53
,
246
(
1974
).
43.
B.
Hartke
, “
Global optimization
,”
Wiley Interdiscip. Rev.: Comput. Mol. Sci.
1
,
879
(
2011
).
44.
M. R.
Aliev
and
J. K. G.
Watson
, “
Calculated sextic centrifugal distortion constants of polyatomic molecules
,”
J. Mol. Spectrosc.
61
,
29
(
1976
).
45.
D.
Papoušek
and
M. R.
Aliev
,
Molecular Vibrational-Rotational Spectra: Theory and Applications of High Resolution Infrared, Microwave and Raman Spectroscopy of Polyatomic Molecules
(
Elsevier Science Ltd.
,
1982
).
46.
M. R.
Aliev
and
J. K. G.
Watson
, “
Higher-order effects in the vibration-rotation spectra of semirigid molecules
,”
Molecular Spectroscopy: Modern Research
(
Academic Press
,
1985
), pp.
1
67
.
47.
G.
Czakó
,
E.
Mátyus
, and
A. G.
Császár
, “
Bridging theory with experiment: A benchmark study of thermally averaged structural and effective spectroscopic parameters of the water molecule
,”
J. Phys. Chem. A
113
,
11665
(
2009
).
48.
G.
Rauhut
, “
Anharmonic Franck-Condon factors for the X̂2B1X̂1A1 photoionization of ketene
,”
J. Phys. Chem. A
119
,
10264
(
2015
).
49.
M.
Tschöpe
,
B.
Schröder
,
S.
Erfort
, and
G.
Rauhut
, “
Highlevel rovibrational calculations on ketenimine
,”
Front. Chem.
8
,
623641
(
2021
).
50.
D. F.
Dinu
,
B.
Ziegler
,
M.
Podewitz
,
K. R.
Liedl
,
T.
Loerting
,
H.
Grothe
, and
G.
Rauhut
, “
The interplay of VSCF/VCI calculations and matrix-isolation IR spectroscopy-mid infraredspectrum of CH3CH2F and CD3CD2F
,”
J. Mol. Spectrosc.
367
,
111224
(
2020
).
51.
H. H.
Nielsen
, “
The vibration-rotation energies of molecules and their spectra in the infra-red
,” in
Handbuch der Physik
, edited by
S.
Flügge
(
Springer
,
Berlin
,
1959
), Vol. 37, Part I, pp.
173
313
.
52.
S.
Urban
and
K. M. T.
Yamada
, “
A breakdown of the watson-type hamiltonian for some asymmetric top molecules
,”
J. Mol. Spectrosc.
160
,
279
(
1993
).
53.
T.
Nakagawa
and
Y.
Morino
, “
Coriolis interactions in the ν4 and ν6 bands of formaldehyde
,”
J. Mol. Spectrosc.
38
,
84
(
1971
).
54.
H. R.
Dübal
and
M.
Quack
, “
Tridiagonal fermi resonance structure in the IR spectrum of the excited CH chromophore in CF3H
,”
J. Chem. Phys.
81
,
3779
(
1984
).
55.
M.
Herman
,
J.
Lievin
,
J. V.
Auwera
,
A.
Campargue
,
I.
Prigogine
, and
S. A.
Rice
, “
The backward trip: From the vibration-rotation data to the Hamiltonian
,” in
Advances in Chemical Physics
(
John Wiley & Sons
,
1999
), pp.
95
253
.
56.
M. K.
Bane
,
E. G.
Robertson
,
C. D.
Thompson
,
D. R. T.
Appadoo
, and
D.
McNaughton
, “
High-resolution Fourier-transform infrared spectroscopy of the ν6 and Coriolis perturbation allowed ν10 modes of ketenimine
,”
J. Chem. Phys.
135
,
224306
(
2011
).
57.
M. S.
Krishnan
and
T.
Carrington
, “
Uncoupled effective hamiltonians for molecules with several vibrational modes coupled byCoriolis and centrifugal terms
,”
Chem. Phys.
219
,
31
(
1997
).
58.
I. M.
Konen
,
E. X. J.
Li
,
M. I.
Lester
,
J.
Vázquez
, and
J. F.
Stanton
, “
Infrared overtone spectroscopy and vibrational analysis of a Fermi resonance in nitric acid: Experiment and theory
,”
J. Chem. Phys.
125
,
074310
(
2006
).
59.
O. J.
Curnow
and
D. L.
Crittenden
, “
Are “Bright-State” models appropriate for analyzing Fermi-Coupled bands in molecular vibrational spectra?
,”
J. Phys. Chem. A
125
,
1355
(
2021
).
60.
P. R.
Franke
,
J. F.
Stanton
, and
G. E.
Douberly
, “
How to VPT2: Accurate and intuitive simulations of CH stretching infrared spectra using VPT2+K with large effective hamiltonian resonance treatments
,”
J. Phys. Chem. A
125
,
1301
(
2021
).
61.
B.
Schröder
and
P.
Sebald
, “
Variational rovibrational calculations for tetra atomic linear molecules using Watson's isomorphic Hamiltonian: II. The B11244 story retold
,”
J. Mol. Spectrosc.
386
,
111628
(
2022
).
62.
T. B.
Adler
,
G.
Knizia
, and
H.-J.
Werner
, “
A simple and efficient CCSD(T)-F12 approximation
,”
J. Chem. Phys.
127
,
221106
(
2007
).
63.
J. G.
Hill
,
S.
Mazumder
, and
K. A.
Peterson
, “
Correlation consistent basis sets for molecular core-valence effects with explicitlycorrelated wave functions: The atoms B–Ne and Al–Ar
,”
J. Chem. Phys.
132
,
054108
(
2010
).
64.
K. A.
Peterson
,
T. B.
Adler
, and
H.-J.
Werner
, “
Systematically convergent basis sets for explicitly correlated wavefunctions: The atoms H, He, B–Ne, and Al–Ar
,”
J. Chem. Phys.
128
,
084102
(
2008
).
65.
H.-J.
Werner
,
G.
Knizia
, and
F. R.
Manby
, “
Explicitly correlated coupled cluster methods with pair-specific geminals
,”
Mol. Phys.
109
,
407
(
2011
).
66.
F.
Weigend
,
A.
Köhn
, and
C.
Hättig
, “
Efficient use of the correlation consistent basis sets in resolution of the identity MP2calculations
,”
J. Chem. Phys.
116
,
3175
(
2002
).
67.
S.
Carter
,
J. M.
Bowman
, and
L. B.
Harding
, “
Ab initio calculations of force fields for H2CN and C1HCN and vibrational energies of H2CN
,”
Spectrochim. Acta, Part A
53
,
1179
(
1997
).
68.
K.
Pflüger
,
M.
Paulus
,
S.
Jagiella
,
T.
Burkert
, and
G.
Rauhut
, “
Multi-level vibrational SCF calculations and FTIR measurements on furazan
,”
Theor. Chem. Acc.
114
,
327
(
2005
).
69.
K.
Yagi
,
S.
Hirata
, and
K.
Hirao
, “
Multiresolution potential energy surfaces for vibrational state calculations
,”
Theor. Chim. Acta
118
,
681
(
2007
).
70.
M.
Sparta
,
M. B.
Hansen
,
E.
Matito
,
D.
Toffoli
, and
O.
Christiansen
, “
Using electronic energy derivative information in automated potential energy surface construction for vibrational calculations
,”
J. Chem. Theory Comput.
6
,
3162
(
2010
).
71.
B.
Ziegler
and
G.
Rauhut
, “
Rigorous use of symmetry within the construction of multidimensional potential energy surfaces
,”
J. Chem. Phys.
149
,
164110
(
2018
).
72.
B.
Ziegler
and
G.
Rauhut
, “
Efficient generation of sum-of products representations of high-dimensional potential energy surfaces based on multimode expansions
,”
J. Chem. Phys.
144
,
114114
(
2016
).
73.
L. L.
Sprandel
, “
Quantum mechanical studies of molecular vibrations
,”
Diss. Abstr. Int. B.
36
,
557
(
1974
).
74.
J. M.
Bowman
, “
Self-consistent field energies and wavefunctions for coupled oscillators
,”
J. Chem. Phys.
68
,
608
(
1978
).
75.
T.
Mathea
and
G.
Rauhut
, “
Assignment of vibrational states within configuration interaction calculations
,”
J. Chem. Phys.
152
,
194112
(
2020
).
76.
T.
Petrenko
and
G.
Rauhut
, “
A new efficient method for the calculation of interior eigenpairs and its application to vibrational structure problems
,”
J. Chem. Phys.
146
,
124101
(
2017
).
77.
C. H.
Townes
and
A. L.
Schawlow
,
Microwave Spectroscopy
(
Dover Publications
,
2019
).
78.
F.
Matsushima
,
H.
Odashima
,
T.
Iwasaki
,
S.
Tsunekawa
, and
K.
Takagi
, “
Frequency measurement of pure rotational transitions of H2O from 0.5 to 5 THz
,”
J. Mol. Struct.
352-353
,
371
(
1995
).
79.
A. G.
Császár
,
C.
Fábri
,
T.
Szidarovszky
,
E.
Mátyus
,
T.
Furtenbacher
, and
G.
Czakó
, “
The fourth age of quantum chemistry: Molecules in motion
,”
Phys. Chem. Chem. Phys.
14
,
1085
(
2012
).
80.
E. K.
Conway
,
I. E.
Gordon
,
O. L.
Polyansky
, and
J.
Tennyson
, “
Determination of quantum labels based on projections of the total angular momentum on the molecule-fixed axis
,”
J. Quant. Spectrosc. Radiat. Transfer
270
,
107716
(
2021
).
81.
S. P.
Belov
,
K. M. T.
Yamada
,
G.
Winnewisser
,
L.
Poteau
,
R.
Bocquet
,
J.
Demaison
,
O.
Polyansky
, and
M. Y.
Tretyakov
, “
Terahertz rotational spectrum of H2S
,”
J. Mol. Spectrosc.
173
,
380
(
1995
).
82.
H. S. P.
Müller
and
F.
Lewen
, “
Submillimeter spectroscopy of H2C17O and a revisit of the rotational spectra of H2C18O and H2C16O
,”
J. Mol. Spectrosc.
331
,
28
(
2017
).
83.
H. S. P.
Müller
,
A.
Maeda
,
S.
Thorwirth
,
F.
Lewen
,
S.
Schlemmer
,
I. R.
Medvedev
,
M.
Winnewisser
,
F. C.
De Lucia
, and
E.
Herbst
, “
Laboratory spectroscopic study of isotopic thioformaldehyde, H2CS, and determination of its equilibrium structure
,”
Astron. Astrophys.
621
,
1
(
2019
).
84.
F.
Matsushima
,
M.
Matsunaga
,
G.-Y.
Qian
,
Y.
Ohtaki
,
R.-L.
Wang
, and
K.
Takagi
, “
Frequency measurement of pure rotational transitions of D2O from 0.5 to 5 THz
,”
J. Mol. Spectrosc.
206
,
41
(
2001
).
85.
P.
Meier
,
D.
Oschetzki
,
R.
Berger
, and
G.
Rauhut
, “
Transformation of potential energy surfaces for estimating isotopic shifts in anharmonic vibrational frequency calculations
,”
J. Chem. Phys.
140
,
184111
(
2014
).
86.
C. P.
Endres
,
S.
Schlemmer
,
P.
Schilke
,
J.
Stutzki
, and
H. S. P.
Müller
, “
The cologne database for molecular spectroscopy, CDMS, in the virtual atomic and molecular data centre, VAMDC
,”
J. Mol. Spectrosc.
327
,
95
(
2016
).
87.
F.
Matsushima
,
N.
Tomatsu
,
T.
Nagai
,
Y.
Moriwaki
, and
K.
Takagi
, “
Frequency measurement of pure rotational transitions in the v2 = 1 state of H2O
,”
J. Mol. Spectrosc.
235
,
190
(
2006
).
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