The benzene radical anion is a molecular ion pertinent to several organic reactions, including the Birch reduction of benzene in liquid ammonia. The species exhibits a dynamic Jahn–Teller effect due to its open-shell nature and undergoes pseudorotation of its geometry. Here, we characterize the complex electronic structure of this condensed-phase system based on ab initio molecular dynamics simulations and GW calculations of the benzene radical anion solvated in liquid ammonia. Using detailed analysis of the molecular and electronic structure, we find that the spatial character of the excess electron of the solvated radical anion follows the underlying Jahn–Teller distortions of the molecular geometry. We decompose the electronic density of states to isolate the contribution of the solute and to examine the response of the solvent to its presence. Our findings show the correspondence between instantaneous molecular structure and spin density; provide important insights into the electronic stability of the species, revealing that it is, indeed, a bound state in the condensed phase; and offer electronic densities of states that aid in the interpretation of experimental photoelectron spectra.

1.
E.
Zurek
,
P. P.
Edwards
, and
R.
Hoffmann
, “
A molecular perspective on lithium-ammonia solutions
,”
Angew. Chem., Int. Ed.
48
,
8198
8232
(
2009
).
2.
M.
Faubel
,
B.
Steiner
, and
J. P.
Toennies
, “
Photoelectron spectroscopy of liquid water, some alcohols, and pure nonane in free micro jets
,”
J. Chem. Phys.
106
,
9013
9031
(
1997
).
3.
T.
Buttersack
,
P. E.
Mason
,
P.
Jungwirth
,
H. C.
Schewe
,
B.
Winter
,
R.
Seidel
,
R. S.
McMullen
, and
S. E.
Bradforth
, “
Deeply cooled and temperature controlled microjets: Liquid ammonia solutions released into vacuum for analysis by photoelectron spectroscopy
,”
Rev. Sci. Instrum.
91
,
043101
(
2020
).
4.
T.
Buttersack
,
P. E.
Mason
,
R. S.
McMullen
,
T.
Martinek
,
K.
Brezina
,
D.
Hein
,
H.
Ali
,
C.
Kolbeck
,
C.
Schewe
,
S.
Malerz
,
B.
Winter
,
R.
Seidel
,
O.
Marsalek
,
P.
Jungwirth
, and
S. E.
Bradforth
, “
Valence and core-level x-ray photoelectron spectroscopy of a liquid ammonia microjet
,”
J. Am. Chem. Soc.
141
,
1838
1841
(
2019
).
5.
T.
Buttersack
,
P. E.
Mason
,
R. S.
McMullen
,
H. C.
Schewe
,
T.
Martinek
,
K.
Brezina
,
M.
Crhan
,
A.
Gomez
,
D.
Hein
,
G.
Wartner
,
R.
Seidel
,
H.
Ali
,
S.
Thürmer
,
O.
Marsalek
,
B.
Winter
,
S. E.
Bradforth
, and
P.
Jungwirth
, “
Photoelectron spectra of alkali metal-ammonia microjets: From blue electrolyte to bronze metal
,”
Science
368
,
1086
1091
(
2020
).
6.
A. J.
Birch
, “
Reduction by dissolving metals
,”
Nature
158
,
585
(
1946
).
7.
T.
Shida
and
S.
Iwata
, “
Electronic spectra of ion radicals and their molecular orbital interpretation. III. Aromatic hydrocarbons
,”
J. Am. Chem. Soc.
95
,
3473
3483
(
1973
).
8.
T. R.
Tuttle
and
S. I.
Weissman
, “
Electron spin resonance spectra of the anions of benzene, toluene and the xylenes
,”
J. Am. Chem. Soc.
80
,
5342
5344
(
1958
).
9.
J. C.
Moore
,
C.
Thornton
,
W. B.
Collier
, and
J. P.
Devlin
, “
Vibrational spectra, Jahn-Teller distortion, and the structure of the benzene radical anion
,”
J. Phys. Chem.
85
,
350
354
(
1981
).
10.
L.
Sanche
and
G. J.
Schulz
, “
Electron transmission spectroscopy: Resonances in triatomic molecules and hydrocarbons
,”
J. Chem. Phys.
58
,
479
493
(
1973
).
11.
A. L.
Hinde
,
D.
Poppinger
, and
L.
Radom
, “
Ab initio study of the benzene radical anion
,”
J. Am. Chem. Soc.
100
,
4681
4685
(
1978
).
12.
A. P.
Bazante
,
E. R.
Davidson
, and
R. J.
Bartlett
, “
The benzene radical anion: A computationally demanding prototype for aromatic anions
,”
J. Chem. Phys.
142
,
204304
(
2015
).
13.
R. A.
Marasas
,
T.
Iyoda
, and
J. R.
Miller
, “
Benzene radical ion in equilibrium with solvated electrons
,”
J. Phys. Chem. A
107
,
2033
2038
(
2003
).
14.
M. C. M.
O’Brien
and
C. C.
Chancey
, “
The Jahn–Teller effect: An introduction and current review
,”
Am. J. Phys.
61
,
688
697
(
1993
).
15.
I. B.
Bersuker
,
The Jahn–Teller Effect
(
Cambridge University Press
,
2006
).
16.
K.
Brezina
,
P.
Jungwirth
, and
O.
Marsalek
, “
Benzene radical anion in the context of the Birch reduction: When solvation is the key
,”
J. Phys. Chem. Lett.
11
,
6032
6038
(
2020
); arXiv:2005.03525.
17.
V.
Kostal
,
K.
Brezina
,
O.
Marsalek
, and
P.
Jungwirth
, “
Benzene radical anion microsolvated in ammonia clusters: Modeling the transition from an unbound resonance to a bound species
,”
J. Phys. Chem. A
125
,
5811
(
2021
).
18.
A.
Glielmo
,
B. E.
Husic
,
A.
Rodriguez
,
C.
Clementi
,
F.
Noé
, and
A.
Laio
, “
Unsupervised learning methods for molecular simulation data
,”
Chem. Rev.
121
,
9722
9758
(
2021
).
19.
P.
Gasparotto
and
M.
Ceriotti
, “
Recognizing molecular patterns by machine learning: An agnostic structural definition of the hydrogen bond
,”
J. Chem. Phys.
141
,
174110
(
2014
); arXiv:1410.5447.
20.
M.
Ceriotti
,
G. A.
Tribello
, and
M.
Parrinello
, “
Simplifying the representation of complex free-energy landscapes using sketch-map
,”
Proc. Natl. Acad. Sci. U. S. A.
108
,
13023
13028
(
2011
).
21.
F.
Hüser
,
T.
Olsen
, and
K. S.
Thygesen
, “
Quasiparticle GW calculations for solids, molecules, and two-dimensional materials
,”
Phys. Rev. B
87
,
235132
(
2013
).
22.
J.
Wilhelm
,
M.
Del Ben
, and
J.
Hutter
, “
GW in the Gaussian and plane waves scheme with application to linear acenes
,”
J. Chem. Theory Comput.
12
,
3623
3635
(
2016
).
23.
J.
Hutter
,
M.
Iannuzzi
,
F.
Schiffmann
, and
J.
VandeVondele
, “
CP2K: Atomistic simulations of condensed matter systems
,”
Wiley Interdiscip. Rev.: Comput. Mol. Sci.
4
,
15
25
(
2014
).
24.
M.
Guidon
,
F.
Schiffmann
,
J.
Hutter
, and
J.
VandeVondele
, “
Ab initio molecular dynamics using hybrid density functionals
,”
J. Chem. Phys.
128
,
214104
(
2008
).
25.
M.
Guidon
,
J.
Hutter
, and
J.
VandeVondele
, “
Robust periodic Hartree–Fock exchange for large-scale simulations using Gaussian basis sets
,”
J. Chem. Theory Comput.
5
,
3010
3021
(
2009
).
26.
G.
Lippert
,
J.
Hutter
, and
M.
Parrinello
, “
A hybrid Gaussian and plane wave density functional scheme
,”
Mol. Phys.
92
,
477
488
(
1997
).
27.
J.
VandeVondele
,
M.
Krack
,
F.
Mohamed
,
M.
Parrinello
,
T.
Chassaing
, and
J.
Hutter
, “
Quickstep: Fast and accurate density functional calculations using a mixed Gaussian and plane waves approach
,”
Comput. Phys. Commun.
167
,
103
128
(
2005
).
28.
G.
Bussi
,
D.
Donadio
, and
M.
Parrinello
, “
Canonical sampling through velocity rescaling
,”
J. Chem. Phys.
126
,
014101
(
2007
); arXiv:0803.4060.
29.
J. P.
Perdew
,
K.
Burke
, and
M.
Ernzerhof
, “
Generalized gradient approximation made simple
,”
Phys. Rev. Lett.
77
,
3865
3868
(
1996
).
30.
Y.
Zhang
and
W.
Yang
, “
Comment on ‘Generalized gradient approximation made simple
,’”
Phys. Rev. Lett.
80
,
890
(
1998
).
31.
C.
Adamo
and
V.
Barone
, “
Toward reliable density functional methods without adjustable parameters: The PBE0 model
,”
J. Chem. Phys.
110
,
6158
6170
(
1999
).
32.
L.
Goerigk
and
S.
Grimme
, “
A thorough benchmark of density functional methods for general main group thermochemistry, kinetics, and noncovalent interactions
,”
Phys. Chem. Chem. Phys.
13
,
6670
6688
(
2011
).
33.
J.
VandeVondele
and
J.
Hutter
, “
Gaussian basis sets for accurate calculations on molecular systems in gas and condensed phases
,”
J. Chem. Phys.
127
,
114105
(
2007
).
34.
S.
Goedecker
and
M.
Teter
, “
Separable dual-space Gaussian pseudopotentials
,”
Phys. Rev. B
54
,
1703
1710
(
1996
); arXiv:9512004 [mtrl-th].
35.
M.
Guidon
,
J.
Hutter
, and
J.
VandeVondele
, “
Auxiliary density matrix methods for Hartree–Fock exchange calculations
,”
J. Chem. Theory Comput.
6
,
2348
2364
(
2010
).
36.
J.
Wilhelm
and
J.
Hutter
, “
Periodic GW calculations in the Gaussian and plane-waves scheme
,”
Phys. Rev. B
95
,
235123
(
2017
).
37.
F.
Ambrosio
,
Z.
Guo
, and
A.
Pasquarello
, “
Absolute energy levels of liquid water
,”
J. Phys. Chem. Lett.
9
,
3212
3216
(
2018
).
38.
A. P.
Gaiduk
,
T. A.
Pham
,
M.
Govoni
,
F.
Paesani
, and
G.
Galli
, “
Electron affinity of liquid water
,”
Nat. Commun.
9
,
247
(
2018
).
39.
P.
Hunt
,
M.
Sprik
, and
R.
Vuilleumier
, “
Thermal versus electronic broadening in the density of states of liquid water
,”
Chem. Phys. Lett.
376
,
68
74
(
2003
).
40.
P.
Fabian
,
M.
Vincent
,
G.
Olivier
,
B.
Mathieu
,
P.
Peter
,
W.
Ron
,
V.
Jake
, and
D.
Cournapeau
, “
Scikit-learn: Machine learning in Python
,”
J. Mach. Learn. Res.
12
,
2825
2830
(
2011
).
41.
P. J.
Rousseeuw
, “
Silhouettes: A graphical aid to the interpretation and validation of cluster analysis
,”
J. Comput. Appl. Math.
20
,
53
65
(
1987
).
42.
R.
Seidel
,
S.
Thürmer
,
J.
Moens
,
P.
Geerlings
,
J.
Blumberger
, and
B.
Winter
, “
Valence photoemission spectra of aqueous Fe2+/3+ and [Fe(CN)6]4−/3− and their interpretation by DFT calculations
,”
J. Phys. Chem. B
115
,
11671
11677
(
2011
).

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