Carbonyl groups (C=O) play crucial roles in the photophysics and photochemistry of biological systems. O1s x-ray photoelectron spectroscopy allows for targeted investigation of the C=O group, and the coupling between C=O vibration and O1s ionization is reflected in the fine structures. To elucidate its characteristic vibronic features, systematic Franck–Condon simulations were conducted for six common biomolecules, including three purines (xanthine, caffeine, and hypoxanthine) and three pyrimidines (thymine, 5F-uracil, and uracil). The complexity of simulation for these biomolecules lies in accounting for temperature effects and potential tautomeric variations. We combined the time-dependent and time-independent methods to efficiently account for the temperature effects and to provide explicit assignments, respectively. For hypoxanthine, the tautomeric effect was considered by incorporating the Boltzmann population ratios of two tautomers. The simulations demonstrated good agreement with experimental spectra, enabling differentiation of two types of carbonyl oxygens with subtle local structural differences, positioned between two nitrogens (O1) or between one carbon and one nitrogen (O2). The analysis provided insights into the coupling between C=O vibration and O1s ionization, consistently showing an elongation of the C=O bond length (by 0.08–0.09 Å) upon O1s ionization.

1.
W.
Hua
,
S.
Mukamel
, and
Y.
Luo
, “
Transient X-ray absorption spectral fingerprints of the S1 dark state in uracil
,”
J. Phys. Chem. Lett.
10
,
7172
7178
(
2019
).
2.
F. A.
Delesma
,
M.
Van den Bossche
,
H.
Grönbeck
,
P.
Calaminici
,
A. M.
Köster
, and
L. G. M.
Pettersson
, “
A chemical view on X-ray photoelectron spectroscopy: The ESCA molecule and surface-to-bulk XPS shifts
,”
ChemPhysChem
19
,
169
174
(
2018
).
3.
J. D.
Andrade
, “
X-Ray photoelectron spectroscopy (XPS)
,” in
Surface and Interfacial Aspects of Biomedical Polymers
, edited by
J. D.
Andrade
(
Springer US
,
Boston, MA
,
1985
), pp.
105
195
.
4.
D.
Ketenoglu
, “
A general overview and comparative interpretation on element‐specific X‐ray spectroscopy techniques: XPS, XAS, and XRS
,”
X-Ray Spectrom.
51
,
422
443
(
2022
).
5.
K.
Siegbahn
,
ESCA Applied to Free Molecules
(
North-Holland Publishing Company
,
1969
).
6.
U.
Gelius
,
S.
Svensson
,
H.
Siegbahn
,
E.
Basilier
,
Å.
Faxälv
, and
K.
Siegbahn
, “
Vibrational and lifetime line broadenings in ESCA
,”
Chem. Phys. Lett.
28
,
1
7
(
1974
).
7.
V.
Carravetta
,
R. C.
Couto
, and
H.
Ågren
, “
X-ray absorption of molecular cations—A new challenge for electronic structure theory
,”
J. Phys.: Condens. Matter
34
,
363002
(
2022
).
8.
U.
Hergenhahn
, “
Vibrational structure in inner shell photoionization of molecules
,”
J. Phys. B: At., Mol. Opt. Phys.
37
,
R89
R135
(
2004
).
9.
S.
Svensson
, “
Soft x-ray photoionization of atoms and molecules
,”
J. Phys. B: At., Mol. Opt. Phys.
38
,
S821
S838
(
2005
).
10.
F.
Duschinsky
, “
The importance of the electron spectrum in multi atomic molecules. Concerning the Franck–Condon principle
,”
Acta Physicochim. URSS
7
,
551
(
1937
).
11.
W.
Hua
,
G.
Tian
, and
Y.
Luo
, “
Theoretical assessment of vibrationally resolved C1s X-ray photoelectron spectra of simple cyclic molecules
,”
Phys. Chem. Chem. Phys.
22
,
20014
20026
(
2020
).
12.
X.
Cheng
,
M.
Wei
,
G.
Tian
,
Y.
Luo
, and
W.
Hua
, “
Vibrationally-resolved X-ray photoelectron spectra of six polycyclic aromatic hydrocarbons from first-principles simulations
,”
J. Phys. Chem. A
126
,
5582
5593
(
2022
).
13.
M.
Wei
,
X.
Cheng
,
L.
Zhang
,
J.-R.
Zhang
,
S.-Y.
Wang
,
G.
Ge
,
G.
Tian
, and
W.
Hua
, “
Vibronic fine structure in the nitrogen 1s photoelectron spectra of molecules from Franck-Condon simulations: Azines
,”
Phys. Rev. A
106
,
022811
(
2022
).
14.
M.
Wei
,
L.
Zhang
,
G.
Tian
, and
W.
Hua
, “
Vibronic fine structure in the nitrogen 1s photoelectron spectra from Franck-Condon simulation. II. Indoles
,”
Phys. Rev. A
108
,
022816
(
2023
).
15.
R. C.
Couto
,
W.
Hua
,
R.
Lindblad
,
L.
Kjellsson
,
S. L.
Sorensen
,
M.
Kubin
,
C.
Bülow
,
M.
Timm
,
V.
Zamudio-Bayer
,
B.
Von Issendorff
,
J.
Söderström
,
J. T.
Lau
,
J.-E.
Rubensson
,
H.
Ågren
, and
V.
Carravetta
, “
Breaking inversion symmetry by protonation: Experimental and theoretical NEXAFS study of the diazynium ion, N2H+
,”
Phys. Chem. Chem. Phys.
23
,
17166
17176
(
2021
).
16.
L.
Sun
,
W.
Hua
,
Y.
Liu
,
G.
Tian
,
M.
Chen
,
M.
Chen
,
F.
Yang
,
S.
Wang
,
X.
Zhang
,
Y.
Luo
, and
W.
Hu
, “
Thermally activated delayed fluorescence in an organic cocrystal: Narrowing the singlet–triplet energy gap via charge transfer
,”
Angew. Chem.
131
,
11433
11438
(
2019
).
17.
H.
Li
,
Z.
Lin
, and
Y.
Luo
, “
Gas-phase IR spectroscopy of deprotonated amino acids: Global or Local minima?
,”
Chem. Phys. Lett.
598
,
86
90
(
2014
).
18.
F.
Santoro
,
A.
Lami
,
R.
Improta
,
J.
Bloino
, and
V.
Barone
, “
Effective method for the computation of optical spectra of large molecules at finite temperature including the Duschinsky and Herzberg–Teller effect: The Qx band of porphyrin as a case study
,”
J. Chem. Phys.
128
,
224311
(
2008
).
19.
O.
Plekan
,
V.
Feyer
,
R.
Richter
,
A.
Moise
,
M.
Coreno
,
K. C.
Prince
,
I. L.
Zaytseva
,
T. E.
Moskovskaya
,
D. Y.
Soshnikov
, and
A. B.
Trofimov
, “
X-Ray spectroscopy of heterocyclic biochemicals: Xanthine, hypoxanthine, and caffeine
,”
J. Phys. Chem. A
116
,
5653
5664
(
2012
).
20.
R.
Berger
,
C.
Fischer
, and
M.
Klessinger
, “
Calculation of the vibronic fine structure in electronic spectra at higher temperatures. 1. Benzene and pyrazine
,”
J. Phys. Chem. A
102
,
7157
7167
(
1998
).
21.
G.
Tian
, “
Electron-vibration coupling and its effects on optical and electronic properties of single molecules
,” Ph.D. thesis,
KTH Royal Institute of Technology
,
2013
.
22.
O.
Plekan
,
V.
Feyer
,
R.
Richter
,
M.
Coreno
,
M.
De Simone
,
K.
Prince
,
A.
Trofimov
,
E.
Gromov
,
I.
Zaytseva
, and
J.
Schirmer
, “
A theoretical and experimental study of the near edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectra (XPS) of nucleobases: Thymine and adenine
,”
Chem. Phys.
347
,
360
375
(
2008
).
23.
V.
Feyer
,
O.
Plekan
,
R.
Richter
,
M.
Coreno
,
G.
Vall-llosera
,
K. C.
Prince
,
A. B.
Trofimov
,
I. L.
Zaytseva
,
T. E.
Moskovskaya
,
E. V.
Gromov
, and
J.
Schirmer
, “
Tautomerism in cytosine and uracil: An experimental and theoretical core level spectroscopic study
,”
J. Phys. Chem. A
113
,
5736
5742
(
2009
).
24.
M. C.
Castrovilli
,
P.
Bolognesi
,
E.
Bodo
,
G.
Mattioli
,
A.
Cartoni
, and
L.
Avaldi
, “
An experimental and theoretical investigation of XPS and NEXAFS of 5-halouracils
,”
Phys. Chem. Chem. Phys.
20
,
6657
6667
(
2018
).
25.
R. M.
Pinto
,
A. A.
Dias
,
M. L.
Costa
,
P.
Rodrigues
,
M. T.
Barros
,
J. S.
Ogden
, and
J. M.
Dyke
, “
Thermal decomposition of methyl 2-azidopropionate studied by UV photoelectron spectroscopy and matrix isolation IR spectroscopy: Heterocyclic intermediate vs imine formation
,”
J. Phys. Chem. A
115
,
8447
8457
(
2011
).
26.
R. M.
Pinto
,
A. A.
Dias
, and
M. L.
Costa
, “
Electronic structure and thermal decomposition of 5-methyltetrazole studied by UV photoelectron spectroscopy and theoretical calculations
,”
Chem. Phys.
392
,
21
28
(
2012
).
27.
J.
Preat
,
A. D.
Laurent
,
C.
Michaux
,
E. A.
Perpète
, and
D.
Jacquemin
, “
Impact of tautomers on the absorption spectra of neutral and anionic alizarin and quinizarin dyes
,”
J. Mol. Struct.: THEOCHEM
901
,
24
30
(
2009
).
28.
N.
Markova
,
V.
Enchev
, and
G.
Ivanova
, “
Tautomeric equilibria of 5-fluorouracil anionic species in water
,”
J. Phys. Chem. A
114
,
13154
13162
(
2010
).
29.
H.
Farrokhpour
and
F.
Fathi
, “
Theoretical study of valance photoelectron spectra of hypoxanthine, xanthine, and caffeine using direct symmetry-adapted cluster/configuration interaction methodology
,”
J. Comput. Chem.
32
,
2479
2491
(
2011
).
30.
V.
Feyer
,
O.
Plekan
,
A.
Kivimäki
,
K. C.
Prince
,
T. E.
Moskovskaya
,
I. L.
Zaytseva
,
D. Y.
Soshnikov
, and
A. B.
Trofimov
, “
Comprehensive core-level study of the effects of isomerism, halogenation, and methylation on the tautomeric equilibrium of cytosine
,”
J. Phys. Chem. A
115
,
7722
7733
(
2011
).
31.
O.
Plekan
,
V.
Feyer
,
R.
Richter
,
M.
Coreno
,
G.
Vall-llosera
,
K. C.
Prince
,
A. B.
Trofimov
,
I. L.
Zaytseva
,
T. E.
Moskovskaya
,
E. V.
Gromov
, and
J.
Schirmer
, “
An experimental and theoretical core-level study of tautomerism in guanine
,”
J. Phys. Chem. A
113
,
9376
9385
(
2009
).
32.
M. Y.
Choi
and
R. E.
Miller
, “
Infrared laser spectroscopy of uracil and thymine in helium nanodroplets: Vibrational transition moment angle study
,”
J. Phys. Chem. A
111
,
2475
2479
(
2007
).
33.
A.
Gerega
,
L.
Lapinski
,
M. J.
Nowak
, and
H.
Rostkowska
, “
UV-induced oxo → hydroxy unimolecular proton-transfer reactions in hypoxanthine
,”
J. Phys. Chem. A
110
,
10236
10244
(
2006
).
34.
P.
Colarusso
,
K.
Zhang
,
B.
Guo
, and
P. F.
Bernath
, “
The infrared spectra of uracil, thymine, and adenine in the gas phase
,”
Chem. Phys. Lett.
269
,
39
48
(
1997
).
35.
P. T.
Ruhoff
and
M. A.
Ratner
, “
Algorithms for computing Franck-Condon overlap integrals
,”
Int. J. Quantum Chem.
77
,
383
392
(
2000
).
36.
Y. J.
Yan
and
S.
Mukamel
, “
Eigenstate-free, Green function, calculation of molecular absorption and fluorescence line shapes
,”
J. Chem. Phys.
85
,
5908
5923
(
1986
).
37.
T.
Sharp
and
H.
Rosenstock
, “
Franck-Condon factors for polyatomic molecules
,”
J. Chem. Phys.
41
,
3453
3463
(
1964
).
38.
P. T.
Ruhoff
, “
Recursion relations for multi-dimensional Franck-Condon overlap integrals
,”
Chem. Phys.
186
,
355
374
(
1994
).
39.
L.
Triguero
,
O.
Plashkevych
,
L.
Pettersson
, and
H.
Ågren
, “
Separate state vs. transition state Kohn-Sham calculations of X-ray photoelectron binding energies and chemical shifts
,”
J. Electron Spectrosc. Relat. Phenom.
104
,
195
207
(
1999
).
40.
M. W.
Schmidt
,
K. K.
Baldridge
,
J. A.
Boatz
,
S. T.
Elbert
,
M. S.
Gordon
,
J. H.
Jensen
,
S.
Koseki
,
N.
Matsunaga
,
K. A.
Nguyen
,
S.
Su
,
T. L.
Windus
,
M.
Dupuis
, and
J. A.
Montgomery
, “
General atomic and molecular electronic structure system
,”
J. Comput. Chem.
14
,
1347
1363
(
1993
).
41.
M. S.
Gordon
and
M. W.
Schmidt
, “
Advances in electronic structure theory: GAMESS a decade later
,” in
Theory and Applications of Computational Chemistry
(
Elsevier
,
2005
), pp.
1167
1189
.
42.
A. D.
Becke
, “
Density-functional exchange-energy approximation with correct asymptotic behavior
,”
Phys. Rev. A
38
,
3098
3100
(
1988
).
43.
A. D.
Becke
, “
A new mixing of Hartree–Fock and local density-functional theories
,”
J. Chem. Phys.
98
,
1372
1377
(
1993
).
44.
C.
Lee
,
W.
Yang
, and
R. G.
Parr
, “
Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density
,”
Phys. Rev. B
37
,
785
789
(
1988
).
45.
T. H.
Dunning
, “
Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen
,”
J. Chem. Phys.
90
,
1007
1023
(
1989
).
46.
R. A.
Kendall
,
T. H.
Dunning
, and
R. J.
Harrison
, “
Electron affinities of the first–row atoms revisited. Systematic basis sets and wave functions
,”
J. Chem. Phys.
96
,
6796
6806
(
1992
).
47.
W.
Kutzelnigg
,
U.
Fleischer
, and
M.
Schindler
, “
The IGLO-method: Ab-initio calculation and interpretation of NMR chemical shifts and magnetic susceptibilities
,” in
Deuterium and Shift Calculation
(
Springer
,
1990
), pp.
165
262
.
48.
Y.
Sakai
,
E.
Miyoshi
,
M.
Klobukowski
, and
S.
Huzinaga
, “
Model potentials for main group elements Li through Rn
,”
J. Chem. Phys.
106
,
8084
8092
(
1997
).
49.
T.
Noro
,
M.
Sekiya
, and
T.
Koga
, “
Contracted polarization functions for the atoms helium through neon
,”
Theor. Chem. Acc.
98
,
25
32
(
1997
).
50.
Segmented Gaussian Basis Set, http://sapporo.center.ims.ac.jp/sapporo/ (accessed on 4 June 2022).
51.
G.
Tian
,
S.
Duan
,
W.
Hua
, and
Y.
Luo
,
DynaVib, version 1.0
(
Royal Institute of Technology
,
Sweden
,
2012
).
52.
C.
Nicolas
and
C.
Miron
, “
Lifetime broadening of core-excited and -ionized states
,”
J. Electron Spectrosc. Relat. Phenom.
185
,
267
272
(
2012
).
53.
X.
Du
,
S.-Y.
Wang
,
M.
Wei
,
J.-R.
Zhang
,
G.
Ge
, and
W.
Hua
, “
A theoretical library of N1s core binding energies of polynitrogen molecules and ions in the gas phase
,”
Phys. Chem. Chem. Phys.
24
,
8196
8207
(
2022
).
54.
W.
Hua
,
B.
Gao
,
S.
Li
,
H.
Ågren
, and
Y.
Luo
, “
X-ray absorption spectra of graphene from first-principles simulations
,”
Phys. Rev. B
82
,
155433
(
2010
).
55.
W.
Hua
,
G.
Tian
,
G.
Fronzoni
,
X.
Li
,
M.
Stener
, and
Y.
Luo
, “
Fe L-edge X-ray absorption spectra of Fe(II) polypyridyl spin crossover complexes from time-dependent density functional theory
,”
J. Phys. Chem. A
117
,
14075
14085
(
2013
).
56.
P. S.
Bagus
,
C.
Sousa
, and
F.
Illas
, “
Consequences of electron correlation for XPS binding energies: Representative case for C(1s) and O(1s) XPS of CO
,”
J. Chem. Phys.
145
,
144303
(
2016
).
57.
N.
Pueyo Bellafont
,
F.
Illas
, and
P. S.
Bagus
, “
Validation of Koopmans’ theorem for density functional theory binding energies
,”
Phys. Chem. Chem. Phys.
17
,
4015
4019
(
2015
).
58.
N.
Pueyo Bellafont
,
P. S.
Bagus
, and
F.
Illas
, “
Prediction of core level binding energies in density functional theory: Rigorous definition of initial and final state contributions and implications on the physical meaning of Kohn-Sham energies
,”
J. Chem. Phys.
142
,
214102
(
2015
).
59.
N.
Pueyo Bellafont
,
F.
Viñes
, and
F.
Illas
, “
Performance of the TPSS functional on predicting core level binding energies of main group elements containing molecules: A good choice for molecules adsorbed on metal surfaces
,”
J. Chem. Theory Comput.
12
,
324
331
(
2016
).
60.
M.
Mendolicchio
,
A.
Baiardi
,
G.
Fronzoni
,
M.
Stener
,
C.
Grazioli
,
M.
De Simone
, and
V.
Barone
, “
Theory meets experiment for unravelling the C1s X-ray photoelectron spectra of pyridine, 2-fluoropyridine, and 2,6-difluoropyridine
,”
J. Chem. Phys.
151
,
124105
(
2019
).
61.
X.
Qiu
,
G.
Tian
,
C.
Lin
,
Y.
Pan
,
X.
Ye
,
B.
Wang
,
D.
Ma
,
D.
Hu
,
Y.
Luo
, and
Y.
Ma
, “
Narrowband emission from organic fluorescent emitters with dominant low-frequency vibronic coupling
,”
Adv. Opt. Mater.
9
,
2001845
(
2021
).
62.
V.
Vaz Da Cruz
,
N.
Ignatova
,
R. C.
Couto
,
D. A.
Fedotov
,
D. R.
Rehn
,
V.
Savchenko
,
P.
Norman
,
H.
Ågren
,
S.
Polyutov
,
J.
Niskanen
,
S.
Eckert
,
R. M.
Jay
,
M.
Fondell
,
T.
Schmitt
,
A.
Pietzsch
,
A.
Föhlisch
,
F.
Gel’mukhanov
,
M.
Odelius
, and
V.
Kimberg
, “
Nuclear dynamics in resonant inelastic X-ray scattering and X-ray absorption of methanol
,”
J. Chem. Phys.
150
,
234301
(
2019
).
63.
J.-C.
Liu
,
C.
Nicolas
,
Y.-P.
Sun
,
R.
Flammini
,
P.
O’Keeffe
,
L.
Avaldi
,
P.
Morin
,
V.
Kimberg
,
N.
Kosugi
,
F.
Gel’mukhanov
, and
C.
Miron
, “
Multimode resonant auger scattering from the ethene molecule
,”
J. Phys. Chem. B
115
,
5103
5112
(
2011
).
64.
V.
Savchenko
,
V.
Ekholm
,
I. E.
Brumboiu
,
P.
Norman
,
A.
Pietzsch
,
A.
Föhlisch
,
J.-E.
Rubensson
,
J.
Gråsjö
,
O.
Björneholm
,
C.
Såthe
,
M.
Dong
,
T.
Schmitt
,
D.
McNally
,
X.
Lu
,
P.
Krasnov
,
S. P.
Polyutov
,
F.
Gel’mukhanov
,
M.
Odelius
, and
V.
Kimberg
, “
Hydrogen bond effects in multimode nuclear dynamics of acetic acid observed via resonant x-ray scattering
,”
J. Chem. Phys.
154
,
214304
(
2021
).
65.
M.
Huang
,
C.
Li
, and
F. A.
Evangelista
, “
Theoretical calculation of core-excited states along dissociative pathways beyond second-order perturbation theory
,”
J. Chem. Theory Comput.
18
,
219
233
(
2022
).
66.
L.
Zhang
,
M.
Wei
,
G.
Ge
, and
W.
Hua
, “
Franck-Condon simulation of vibrationally resolved x-ray spectra for diatomic systems: Validation of the harmonic approximation and density functional theory
,”
Phys. Rev. A
109
,
032815
(
2024
).
67.
A.
Anda
,
L.
De Vico
,
T.
Hansen
, and
D.
Abramavičius
, “
Absorption and fluorescence lineshape theory for polynomial potentials
,”
J. Chem. Theory Comput.
12
,
5979
5989
(
2016
).
68.
T. J.
Zuehlsdorff
,
A.
Montoya-Castillo
,
J. A.
Napoli
,
T. E.
Markland
, and
C. M.
Isborn
, “
Optical spectra in the condensed phase: Capturing anharmonic and vibronic features using dynamic and static approaches
,”
J. Chem. Phys.
151
,
074111
(
2019
).
69.
R.
Borrelli
,
A.
Capobianco
, and
A.
Peluso
, “
Generating function approach to the calculation of spectral band shapes of free-base chlorin including Duschinsky and Herzberg–Teller effects
,”
J. Phys. Chem. A
116
,
9934
9940
(
2012
).
70.
T.
Begušić
,
A.
Patoz
,
M.
Šulc
, and
J.
Vaníček
, “
On-the-fly ab initio three thawed Gaussians approximation: A semiclassical approach to Herzberg-Teller spectra
,”
Chem. Phys.
515
,
152
163
(
2018
).
71.
B.
De Souza
,
F.
Neese
, and
R.
Izsák
, “
On the theoretical prediction of fluorescence rates from first principles using the path integral approach
,”
J. Chem. Phys.
148
,
034104
(
2018
).
72.
F.-F.
Kong
,
X.-J.
Tian
,
Y.
Zhang
,
Y.-J.
Yu
,
S.-H.
Jing
,
Y.
Zhang
,
G.-J.
Tian
,
Y.
Luo
,
J.-L.
Yang
,
Z.-C.
Dong
, and
J. G.
Hou
, “
Probing intramolecular vibronic coupling through vibronic-state imaging
,”
Nat. Commun.
12
,
1280
(
2021
).
73.
F.
Montorsi
,
F.
Segatta
,
A.
Nenov
,
S.
Mukamel
, and
M.
Garavelli
, “
Soft X-ray spectroscopy simulations with multiconfigurational wave function theory: Spectrum completeness, sub-eV accuracy, and quantitative reproduction of line shapes
,”
J. Chem. Theory Comput.
18
,
1003
1016
(
2022
).
You do not currently have access to this content.