We systematically investigated the structural evolution of boron (B) and aluminum (Al) hydrides using various DFT and ab initio methods, aiming to reveal the similarities and differences in their geometric and electronic structures. While B hydrides have been extensively studied both experimentally and theoretically, less is known about its group 13 heavier congener, Al. Extensive global minimum searches of the B2Hx (Al2Hx) and B3Hy (Al3Hy) hydrides (x = [0–6], y = [0–9]) were performed to identify the most stable geometric structures for each stoichiometry. In most of the series, B and Al hydrides exhibit qualitatively different structures, except for the most saturated X2H5 and X2H6 stoichiometries. Chemical bonding analyses employing adaptive natural density partitioning and electron localization function methods identified notable differences between B and Al hydrides in most of the compositions. B hydrides predominantly possess two-center (2c) and three-center (3c) bonding elements, suggesting a relatively balanced electron distribution. On the contrary, Al hydrides tend to retain unpaired electrons or lone pairs on Al atoms, forming a large number of closely lying isomers with various combinations of 1c, 2c, 3c, and 4c bonding elements. Thermodynamic stability analyses revealed that all studied clusters demonstrated stability toward various H/H2 dissociation pathways, with Al hydrides being less stable than B counterparts.

1.
S. X.
Tian
, “
Ab initio and electron propagator theory study of boron hydrides
,”
J. Phys. Chem. A
109
(
24
),
5471
5480
(
2005
).
2.
M. A.
Vincent
and
H. F.
Schaefer
, “
Diborane(4) (B2H4): The boron hydride analog of ethylene
,”
J. Am. Chem. Soc.
103
(
19
),
5677
5680
(
1981
).
3.
B. I.
Loukhovitski
,
S. A.
Torokhov
,
E. E.
Loukhovitskaya
, and
A. S.
Sharipov
, “
DFT study of small aluminum and boron hydrides: Isomeric composition and physical properties
,”
Struct. Chem.
29
(
1
),
49
68
(
2018
).
4.
B.
Wrackmeyer
, “
Indirect nuclear spin-spin coupling constants nJ(11B,1H) and nJ(11B, 11B) in some boron hydrides—density functional theory (DFT) calculations
,”
Z. Naturforsch. B
59
(
11–12
),
1192
1199
(
2004
).
5.
S. J.
Wilkens
,
W. M.
Westler
,
F.
Weinhold
, and
J. L.
Markley
, “
Trans-hydrogen-bond h2JNN and h1JNH couplings in the DNA A−T base pair: Natural bond orbital analysis
,”
J. Am. Chem. Soc.
124
(
7
),
1190
1191
(
2002
).
6.
I.
Matsuda
and
K.
Wu
,
2D Boron: Boraphene, Borophene, Boronene
(
Springer International Publishing
,
Cham
,
2021
).
7.
H. J.
Emeléus
and
A. G.
Sharpe
,
Advances in Inorganic Chemistry and Radiochemistry
(
Academic Press
,
New York and London
,
1967
).
8.
A.
Francés-Monerris
,
J.
Holub
,
D.
Roca-Sanjuán
,
D.
Hnyk
,
K.
Lang
, and
J. M.
Oliva-Enrich
, “
Photochromic system among boron hydrides: The Hawthorne rearrangement
,”
J. Phys. Chem. Lett.
10
(
20
),
6202
6207
(
2019
).
9.
Q.
Yao
,
Y.
Ding
, and
Z.-H.
Lu
, “
Noble-metal-free nanocatalysts for hydrogen generation from boron- and nitrogen-based hydrides
,”
Inorg. Chem. Front.
7
(
20
),
3837
3874
(
2020
).
10.
W.-H.
Yang
,
W.-C.
Lu
,
S.-D.
Li
,
X.-Y.
Xue
,
W.
Qin
,
K. M.
Ho
, and
C. Z.
Wang
, “
Superconductivity in alkaline earth metal doped boron hydrides
,”
Phys. B: Condens. Matter
611
,
412795
(
2021
).
11.
H.
Gao
,
R.
Müller
,
E.
Irran
,
H. F. T.
Klare
,
M.
Kaupp
, and
M.
Oestreich
, “
Competition for hydride between silicon and boron: Synthesis and characterization of a hydroborane‐stabilized silylium ion
,”
Chem. – Eur. J.
28
(
12
),
e202104464
(
2022
).
12.
E. R.
Burkhardt
and
K.
Matos
, “
Boron reagents in process chemistry: Excellent tools for selective reductions
,”
Chem. Rev.
106
(
7
),
2617
2650
(
2006
).
13.
L. J.
Donnelly
,
S.
Parsons
,
C. A.
Morrison
,
S. P.
Thomas
, and
J. B.
Love
, “
Synthesis and structures of anionic rhenium polyhydride complexes of boron–hydride ligands and their application in catalysis
,”
Chem. Sci.
11
(
36
),
9994
9999
(
2020
).
14.
A. A.
Semioshkin
,
I. B.
Sivaev
, and
V. I.
Bregadze
, “
Cyclic oxonium derivatives of polyhedral boron hydrides and their synthetic applications
,”
Dalton Trans.
2008
(
8
),
977
992
.
15.
E.
Fakioglu
,
Y.
Yurum
, and
T. N.
Veziroglu
, “
A review of hydrogen storage systems based on boron and its compounds
,”
Int. J. Hydrogen Energy
29
(
13
),
1371
1376
(
2004
).
16.
H.
Hagemann
, “
Boron Hydrogen Compounds: Hydrogen storage and battery applications
,”
Molecules
26
(
24
),
7425
(
2021
).
17.
E.
Meydan
, “
Boron compounds with magnetic properties and their application areas in industry
,”
Health Sci. Q.
3
(
1
),
11
20
(
2019
).
18.
Z. J.
Leśnikowski
, “
Recent developments with boron as a platform for novel drug design
,”
Expert Opin. Drug Discovery
11
(
6
),
569
578
(
2016
).
19.
N. N.
Greenwood
, “
Ludwig Mond lecture. Taking stock: The astonishing development of boron hydride cluster chemistry
,”
Chem. Soc. Rev.
21
(
1
),
49
(
1992
).
20.
N. W.
Mitzel
, “
Molecular dialane and other binary hydrides
,”
Angew. Chem. Int. Ed.
42
(
33
),
3856
3858
(
2003
).
21.
F. A.
Cotton
,
G.
Wilkinson
,
C. A.
Murillo
, and
M.
Bochmann
,
Advanced Inorganic Chemistry
(
John Wiley & Sons
,
1999
).
22.
L.
Andrews
and
X.
Wang
, “
The Infrared spectrum of Al2H6 in solid hydrogen
,”
Science
299
(
5615
),
2049
2052
(
2003
).
23.
J. W.
Turley
and
H. W.
Rinn
, “
Crystal structure of aluminum hydride
,”
Inorg. Chem.
8
(
1
),
18
22
(
1969
).
24.
F. M.
Brower
,
N. E.
Matzek
,
P. F.
Reigler
,
H. W.
Rinn
,
C. B.
Roberts
,
D. L.
Schmidt
,
J. A.
Snover
, and
K.
Terada
, “
Preparation and properties of aluminum hydride
,”
J. Am. Chem. Soc.
98
(
9
),
2450
2453
(
1976
).
25.
A. J.
Downs
and
C. R.
Pulham
, “
The hydrides of aluminium, gallium, indium, and thallium: A re-evaluation
,”
Chem. Soc. Rev.
23
(
3
),
175
(
1994
).
26.
P.
Pullumbi
,
C.
Mijoule
,
L.
Manceron
, and
Y.
Bouteiller
, “
Aluminium, gallium and indium dihydrides. An IR matrix isolation and ab initio study
,”
Chem. Phys.
185
(
1
),
13
24
(
1994
).
27.
C. R.
Pulham
,
A. J.
Downs
,
M. J.
Goode
,
D. W. H.
Rankin
, and
H. E.
Robertson
, “
Gallane: Synthesis, physical and chemical properties, and structure of the gaseous molecule Ga2H6 as determined by electron diffraction
,”
J. Am. Chem. Soc.
113
(
14
),
5149
5162
(
1991
).
28.
H.-J.
Himmel
,
L.
Manceron
,
A. J.
Downs
, and
P.
Pullumbi
, “
Formation and characterization of the gallium and indium subhydride molecules Ga2H2 and In2H2 : A matrix isolation study
,”
J. Am. Chem. Soc.
124
(
16
),
4448
4457
(
2002
).
29.
M.-T.
Wei
and
S.-J.
Jiang
, “
Determination of thallium in sea-water by flow injection hydride generation isotope dilution inductively coupled plasma mass spectrometry
,”
J. Anal. At. Spectrom.
14
(
8
),
1177
1181
(
1999
).
30.
R.-D.
Urban
,
A. H.
Bahnmaier
,
U.
Magg
, and
H.
Jones
, “
The diode laser spectrum of thallium hydride (205TlH and 203TlH) in its ground electronic state
,”
Chem. Phys. Lett.
158
(
5
),
443
446
(
1989
).
31.
E. A.
Piocos
and
B. S.
Ault
, “
Matrix isolation study of the molecular complexes of trimethylgallium with group V bases
,”
J. Phys. Chem.
96
(
19
),
7589
7593
(
1992
).
32.
Y.
Liu
,
D.
Duan
,
F.
Tian
,
H.
Liu
,
C.
Wang
,
X.
Huang
,
D.
Li
,
Y.
Ma
,
B.
Liu
, and
T.
Cui
, “
Pressure-induced structures and properties in indium hydrides
,”
Inorg. Chem.
54
(
20
),
9924
9928
(
2015
).
33.
G.
Gao
,
H.
Wang
,
A.
Bergara
,
Y.
Li
,
G.
Liu
, and
Y.
Ma
, “
Metallic and superconducting gallane under high pressure
,”
Phys. Rev. B
84
(
6
),
064118
(
2011
).
34.
D.
Duan
,
Y.
Liu
,
Y.
Ma
,
Z.
Shao
,
B.
Liu
, and
T.
Cui
, “
Structure and superconductivity of hydrides at high pressures
,”
Natl. Sci. Rev.
4
(
1
),
121
135
(
2017
).
35.
L.
Andrews
and
X.
Wang
, “
Infrared spectra of indium hydrides in solid hydrogen and of solid indane
,”
Angew. Chem. Int. Ed.
43
,
1706
1709
(
2004
).
36.
J.
Graetz
,
J. J.
Reilly
,
J. G.
Kulleck
, and
R. C.
Bowman
, “
Kinetics and thermodynamics of the aluminum hydride polymorphs
,”
J. Alloys Compd.
446–447
,
271
275
(
2007
).
37.
C.
Jones
, “
The stabilisation and reactivity of indium trihydride complexes
,”
Chem. Commun.
2001
,
2293
2298
.
38.
T.
Miyai
,
K.
Inoue
,
M.
Yasuda
,
I.
Shibata
, and
A.
Baba
, “
Preparation of a novel indium hydride and application to practical organic synthesis
,”
Tetrahedron Lett.
39
(
14
),
1929
1932
(
1998
).
39.
M. L.
Cole
,
D. E.
Hibbs
,
C.
Jones
, and
N. A.
Smithies
, “
Phosphine and phosphido indium hydride complexes and their use in inorganic synthesis
,”
J. Chem. Soc., Dalton Trans.
2000
(
4
),
545
550
.
40.
A. S.
Pozdeev
,
P.
Rublev
,
A. I.
Boldyrev
, and
Y.
Rao
, “
Global minimum search and bonding analysis of Tl2Hx and Tl3Hy (x=0–6; y=0–5) series
,”
ChemPhysChem
24
(
17
),
e202300332
(
2023
).
41.
A. S.
Pozdeev
,
P.
Rublev
,
S.
Scheiner
, and
A. I.
Boldyrev
, “
Theoretical investigation of geometries and bonding of indium hydrides in the In2Hx and In3Hy (x = 0–4,6; y = 0–5) series
,”
Molecules
28
(
1
),
183
(
2022
).
42.
A. P.
Sergeeva
,
B. B.
Averkiev
,
H.-J.
Zhai
,
A. I.
Boldyrev
, and
L.-S.
Wang
, “
All-boron analogues of aromatic hydrocarbons: B17 and B18
,”
J. Chem. Phys.
134
(
22
),
224304
(
2011
).
43.
A. S.
Pozdeev
,
W.-J.
Chen
,
M.
Kulichenko
,
H. W.
Choi
,
A. I.
Boldyrev
, and
L.-S.
Wang
, “
On the structures and bonding of copper boride nanoclusters, Cu2B (x = 5–7)
,”
Solid State Sci.
142
,
107248
(
2023
).
44.
M.
Kulichenko
,
W.-J.
Chen
,
H. W.
Choi
,
D.-F.
Yuan
,
A. I.
Boldyrev
, and
L.-S.
Wang
, “
Probing copper-boron interactions in the Cu2B8 bimetallic cluster
,”
J. Vac. Sci. Technol. A
40
(
4
),
042201
(
2022
).
45.
P.
Rublev
,
N. V.
Tkachenko
,
P. A.
Dub
, and
A. I.
Boldyrev
, “
On the existence of CO32− microsolvated clusters: A theoretical study
,”
Phys. Chem. Chem. Phys.
25
(
20
),
14046
14055
(
2023
).
46.
P.
Rublev
,
N. V.
Tkachenko
,
A. S.
Pozdeev
, and
A. I.
Boldyrev
, “
Tinning the carbon: Hydrostannanes strike back
,”
Dalton Trans.
52
(
1
),
29
36
(
2023
).
47.
P.
Das
and
P. K.
Chattaraj
, “
In silico studies on selected neutral molecules, CGa2Ge2, CAlGaGe2, and CSiGa2Ge containing planar tetracoordinate carbon
,”
Atoms
9
(
3
),
65
(
2021
).
48.
Y.-J.
Yang
,
S.-X.
Li
,
D.-L.
Chen
, and
Z.-W.
Long
, “
Structural evolution and electronic properties of selenium-doped boron clusters SeBn0/− (n = 3–16)
,”
Molecules
28
(
1
),
357
(
2023
).
49.
Z.
Xiang
,
Z.
Luo
,
J.
Bi
,
S.
Jin
,
Z.
Zhang
, and
C.
Lu
, “
Structural evolution and relative stability of vanadium-doped boron clusters
,”
J. Phys.: Condens. Matter
34
(
44
),
445302
(
2022
).
50.
W.-L.
Li
,
Y.-F.
Zhao
,
H.-S.
Hu
,
J.
Li
, and
L.-S.
Wang
, “
[B30]: A quasiplanar chiral boron cluster
,”
Angew. Chem., Int. Ed. Engl.
53
(
22
),
5540
5545
(
2014
).
51.
Y.-S.
Huang
,
Y.
Xue
,
A.
Muñoz-Castro
,
I. A.
Popov
, and
Z.-M.
Sun
, “
[Nb@Ge13/14]3−: New family members of Ge-based intermetalloid clusters
,”
Chem. – Eur. J.
28
(
62
),
e202202192
(
2022
).
52.
A. S.
Pozdeev
,
P.
Rublev
, and
A. I.
Boldyrev
, “
Bismuth infrared star: Being at a glance
,”
Chem. – Eur. J.
29
(
69
),
e202301663
(
2023
).
53.
A.
Savin
,
R.
Nesper
,
S.
Wengert
, and
T. F.
Fässler
, “
ELF: The electron localization function
,”
Angew. Chem., Int. Ed. Engl.
36
(
17
),
1808
1832
(
1997
).
54.
M.
Saunders
, “
Stochastic search for isomers on a quantum mechanical surface
,”
J. Comput. Chem.
25
(
5
),
621
626
(
2004
).
55.
H. S.
Yu
,
X.
He
,
S. L.
Li
, and
D. G.
Truhlar
, “
MN15: A Kohn–Sham global-hybrid exchange–correlation density functional with broad accuracy for multi-reference and single-reference systems and noncovalent interactions
,”
Chem. Sci.
7
(
8
),
5032
5051
(
2016
).
56.
F.
Weigend
and
R.
Ahlrichs
, “
Balanced basis sets of split valence, triple zeta valence and quadruple zeta valence quality for H to Rn: Design and assessment of accuracy
,”
Phys. Chem. Chem. Phys.
7
(
18
),
3297
(
2005
).
57.
M. J.
Frisch
,
G. W.
Trucks
,
H. B.
Schlegel
,
G. E.
Scuseria
,
M. A.
Robb
,
J. R.
Cheeseman
,
G.
Scalmani
,
V.
Barone
,
G. A.
Petersson
,
H.
Nakatsuji
,
X.
Li
,
M.
Caricato
,
A. V.
Marenich
,
J.
Bloino
,
B. G.
Janesko
,
R.
Gomperts
,
B.
Mennucci
,
H. P.
Hratchian
,
J. V.
Ortiz
,
A. F.
Izmaylov
,
J. L.
Sonnenberg
,
D.
Williams-Young
,
F.
Ding
,
F.
Lipparini
,
F.
Egidi
,
J.
Goings
,
B.
Peng
,
A.
Petrone
,
T.
Henderson
,
D.
Ranasinghe
,
V. G.
Zakrzewski
,
J.
Gao
,
N.
Rega
,
G.
Zheng
,
W.
Liang
,
M.
Hada
,
M.
Ehara
,
K.
Toyota
,
R.
Fukuda
,
J.
Hasegawa
,
M.
Ishida
,
T.
Nakajima
,
Y.
Honda
,
O.
Kitao
,
H.
Nakai
,
T.
Vreven
,
K.
Throssell
,
J. A.
Montgomery
, Jr.
,
J. E.
Peralta
,
F.
Ogliaro
,
M. J.
Bearpark
,
J. J.
Heyd
,
E. N.
Brothers
,
K. N.
Kudin
,
V. N.
Staroverov
,
T. A.
Keith
,
R.
Kobayashi
,
J.
Normand
,
K.
Raghavachari
,
A. P.
Rendell
,
J. C.
Burant
,
S. S.
Iyengar
,
J.
Tomasi
,
M.
Cossi
,
J. M.
Millam
,
M.
Klene
,
C.
Adamo
,
R.
Cammi
,
J. W.
Ochterski
,
R. L.
Martin
,
K.
Morokuma
,
O.
Farkas
,
J. B.
Foresman
, and
D. J.
Fox
,
Gaussian 16, Revision C.01
(
Gaussian, Inc
.,
Wallingford CT
,
2016
).
58.
V. N.
Staroverov
,
G. E.
Scuseria
,
J.
Tao
, and
J. P.
Perdew
, “
Comparative assessment of a new nonempirical density functional: Molecules and hydrogen-bonded complexes
,”
J. Chem. Phys.
119
(
23
),
12129
12137
(
2003
).
59.
J.
Tao
,
J. P.
Perdew
,
V. N.
Staroverov
, and
G. E.
Scuseria
, “
Climbing the density functional ladder: nonempirical meta–generalized gradient approximation designed for molecules and solids
,”
Phys. Rev. Lett.
91
(
14
),
146401
(
2003
).
60.
S.
Grimme
and
A.
Hansen
, “
A practicable real-space measure and visualization of static electron-correlation effects
,”
Angew. Chem., Int. Ed. Engl.
54
(
42
),
12308
12313
(
2015
).
61.
C.
Angeli
,
S.
Borini
,
M.
Cestari
, and
R.
Cimiraglia
, “
A quasidegenerate formulation of the second order n-electron valence state perturbation theory approach
,”
J. Chem. Phys.
121
(
9
),
4043
4049
(
2004
).
62.
F.
Jensen
, “
Polarization consistent basis sets: Principles
,”
J. Chem. Phys.
115
(
20
),
9113
9125
(
2001
).
63.
F.
Jensen
, “
Polarization consistent basis sets. II. Estimating the Kohn–Sham basis set limit
,”
J. Chem. Phys.
116
(
17
),
7372
7379
(
2002
).
64.
F.
Jensen
, “
Polarization consistent basis sets. III. The importance of diffuse functions
,”
J. Chem. Phys.
117
(
20
),
9234
9240
(
2002
).
65.
F.
Jensen
, “
Polarization consistent basis sets. 4: the elements He, Li, Be, B, Ne, Na, Mg, Al, and Ar
,”
J. Phys. Chem. A
111
(
44
),
11198
11204
(
2007
).
66.
R.
Bauernschmitt
and
R.
Ahlrichs
, “
Stability analysis for solutions of the closed shell Kohn–Sham equation
,”
J. Chem. Phys.
104
(
22
),
9047
9052
(
1996
).
67.
F.
Neese
, “
The ORCA program system
,”
Wiley Interdiscip. Rev. Comput. Mol. Sci.
2
(
1
),
73
78
(
2012
).
68.
F.
Neese
, “
Software update: The ORCA program system—version 5.0
,”
WIREs Comput. Mol. Sci.
12
(
5
),
e1606
(
2022
).
69.
A.
Kumar
,
F.
Neese
, and
E. F.
Valeev
, “
Explicitly correlated coupled cluster method for accurate treatment of open-shell molecules with hundreds of atoms
,”
J. Chem. Phys.
153
(
9
),
094105
(
2020
).
70.
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
(
8
),
084102
(
2008
).
71.
K. E.
Yousaf
and
K. A.
Peterson
, “
Optimized auxiliary basis sets for explicitly correlated methods
,”
J. Chem. Phys.
129
(
18
),
184108
(
2008
).
72.
O.
Vahtras
,
J.
Almlöf
, and
M. W.
Feyereisen
, “
Integral approximations for LCAO-SCF calculations
,”
Chem. Phys. Lett.
213
(
5
),
514
518
(
1993
).
73.
D. Yu.
Zubarev
and
A. I.
Boldyrev
, “
Developing paradigms of chemical bonding: adaptive natural density partitioning
,”
Phys. Chem. Chem. Phys.
10
(
34
),
5207
(
2008
).
74.
N. V.
Tkachenko
and
A. I.
Boldyrev
, “
Chemical bonding analysis of excited states using the adaptive natural density partitioning method
,”
Phys. Chem. Chem. Phys.
21
(
18
),
9590
9596
(
2019
).
75.
T.
Lu
and
F.
Chen
, “
Multiwfn: A multifunctional wavefunction analyzer
,”
J. Comput. Chem.
33
(
5
),
580
592
(
2012
).
76.
N. V.
Tkachenko
,
W.-X.
Chen
,
H. W. T.
Morgan
,
A.
Muñoz-Castro
,
A. I.
Boldyrev
, and
Z.-M.
Sun
, “
Sn368− : A 2.7 nm naked aromatic tin rod
,”
Chem. Commun.
58
(
42
),
6223
6226
(
2022
).
77.
I. A.
Popov
,
X.
Zhang
,
B. W.
Eichhorn
,
A. I.
Boldyrev
, and
K. H.
Bowen
, “
Aluminum chain in Li2Al3H8 as suggested by photoelectron spectroscopy and ab initio calculations
,”
Phys. Chem. Chem. Phys.
17
(
39
),
26079
26083
(
2015
).
78.
J.-C.
Guo
,
L.-Y.
Feng
,
Y.-J.
Wang
,
S.
Jalife
,
A.
Vásquez-Espinal
,
J. L.
Cabellos
,
S.
Pan
,
G.
Merino
, and
H.-J.
Zhai
, “
Coaxial triple-layered versus helical Be6B11 clusters: Dual structural fluxionality and multifold aromaticity
,”
Angew. Chem., Int. Ed. Engl.
56
(
34
),
10174
10177
(
2017
).
79.
Y.
Wang
,
X.
Shi
,
W.
Wu
,
X.
Deng
,
K.
Xin
,
Z.
Zhou
,
L.
Tang
, and
Z.
Ning
, “
Theoretical exploration of peculiar sandwich-type clusters formed by the coordination of E92− (E = Si, Ge, Sn) Zintl clusters: Structural properties, active sites, and hydrogen Storage
,”
Langmuir
38
(
47
),
14485
14496
(
2022
).
80.
S.
Guin
,
S. R.
Ghosh
, and
A. D.
Jana
, “
First report of a planar and a quasi-planar Al13+ cluster having localized antiaromatic deltas within an aromatic sea: NICS, ELF, AIM, and AdNDP bonding analysis
,”
J. Mol. Model
24
(
12
),
344
(
2018
).
81.
H.-J.
Zhai
,
J.-C.
Guo
,
S.-D.
Li
, and
L.-S.
Wang
, “
Bridging η2-BO in B2(BO)3 and B3(BO)3 clusters: Boronyl analogs of boranes
,”
ChemPhysChem
12
(
14
),
2549
2553
(
2011
).
82.
A. S.
Pozdeev
,
W.-J.
Chen
,
H. W.
Choi
,
M.
Kulichenko
,
D.-F.
Yuan
,
A. I.
Boldyrev
, and
L.-S.
Wang
, “
Photoelectron spectroscopy and theoretical Study of di-copper–boron clusters: Cu2B3 and Cu2B4
,”
J. Phys. Chem. A
127
(
22
),
4888
4896
(
2023
).
83.
A. S.
Pozdeev
,
A. I.
Boldyrev
, and
Y.
Rao
, “
Chemical bonding in lead anionic clusters
,”
Polyhedron
243
,
116572
(
2023
).
84.
J.
Pipek
and
P. G.
Mezey
, “
A fast intrinsic localization procedure applicable for ab initio and semiempirical linear combination of atomic orbital wave functions
,”
J. Chem. Phys.
90
(
9
),
4916
4926
(
1989
).
85.
S. F.
Boys
, “
Construction of some molecular orbitals to be approximately invariant for changes from one molecule to another
,”
Rev. Mod. Phys.
32
(
2
),
296
299
(
1960
).
86.
F.
Weinhold
and
C. R.
Landis
, “
Natural bond orbitals and extensions of localized bonding concepts
,”
Chem. Educ. Res. Pract.
2
(
2
),
91
104
(
2001
).
87.
B. O.
Roos
,
P. R.
Taylor
, and
P. E. M.
Sigbahn
, “
A complete active space SCF method (CASSCF) using a density matrix formulated super-CI approach
,”
Chem. Phys.
48
(
2
),
157
173
(
1980
).
88.
M. P.
Kelley
,
I. A.
Popov
,
J.
Jung
,
E. R.
Batista
, and
P.
Yang
, “
δ and φ back-donation in AnIV metallacycles
,”
Nat. Commun.
11
(
1
),
1558
(
2020
).
89.
M.
Kulichenko
,
N.
Fedik
,
A.
Boldyrev
, and
A.
Muñoz-Castro
, “
Expansion of magnetic aromaticity criteria to multilayer structures: Magnetic response and spherical aromaticity of matryoshka-like cluster [Sn@Cu12@Sn20]12
,”
Chem. – Eur. J.
26
(
10
),
2263
2268
(
2020
).
90.
A. P.
Sergeeva
and
A. I.
Boldyrev
, “
The chemical bonding of Re3Cl9 and Re3Cl92- revealed by the adaptive natural density partioning analyses
,”
Comments Inorg. Chem.
31
(
1–2
),
2
12
(
2010
).
91.
A. D.
Becke
and
K. E.
Edgecombe
, “
A simple measure of electron localization in atomic and molecular systems
,”
J. Chem. Phys.
92
(
9
),
5397
5403
(
1990
).
92.
J. I.
Rodríguez
,
A. M.
Köster
,
P. W.
Ayers
,
A.
Santos-Valle
,
A.
Vela
, and
G.
Merino
, “
An efficient grid-based scheme to compute QTAIM atomic properties without explicit calculation of zero-flux surfaces
,”
J. Comput. Chem.
30
(
7
),
1082
1092
(
2009
).
93.
J. I.
Rodríguez
,
R. F. W.
Bader
,
P. W.
Ayers
,
C.
Michel
,
A. W.
Götz
, and
C.
Bo
, “
A high performance grid-based algorithm for computing QTAIM properties
,”
Chem. Phys. Lett.
472
(
1–3
),
149
152
(
2009
).
94.
A.
Altun
,
M.
Saitow
,
F.
Neese
, and
G.
Bistoni
, “
Local energy decomposition of open-shell molecular systems in the domain-based local pair natural orbital coupled cluster framework
,”
J. Chem. Theory Comput.
15
(
3
),
1616
1632
(
2019
).
95.
See https://www.chemcraftprog.com for
Chemcraft—graphical software for visualization of quantum chemistry computations
. Version 1.8, build 682.
96.
C. F.
Bender
and
E. R.
Davidson
, “
Electronic structure of the B2 molecule
,”
J. Chem. Phys.
46
(
9
),
3313
3319
(
1967
).
97.
T. H.
Upton
, “
Low-lying valence electronic states of the aluminum dimer
,”
J. Phys. Chem.
90
(
5
),
754
759
(
1986
).
98.
L. B.
Knight
, Jr.
,
K.
Kerr
,
P. K.
Miller
, and
C. A.
Arrington
, “
ESR investigation of the HBBH(X3.SIGMA.) radical in neon and argon matrixes at 4 K. Comparison with ab initio SCF and CI calculations
,”
J. Phys. Chem.
99
(
46
),
16842
16848
(
1995
).
99.
T. J.
Tague
and
L.
Andrews
, “
Reactions of pulsed-laser evaporated boron atoms with hydrogen. Infrared spectra of boron hydride intermediate species in solid argon
,”
J. Am. Chem. Soc.
116
(
11
),
4970
4976
(
1994
).
100.
Z.
Palagyi
,
R. S.
Grev
, and
H. F. I.
Schaefer
, “
Striking similarities between elementary silicon and aluminum compounds: Monobridged, dibridged, trans-bent, and vinylidene isomers of aluminum hydride (Al2H2)
,”
J. Am. Chem. Soc.
115
(
5
),
1936
1943
(
1993
).
101.
D. B.
Chesnut
, “
A topological study of bonding in the Al2H2 and Al2H4 hydrides
,”
Chem. Phys.
321
(
3
),
269
276
(
2006
).
102.
J. C.
Stephens
,
E. E.
Bolton
,
H. F.
Schaefer
, and
L.
Andrews
, “
Quantum mechanical frequencies and matrix assignments to Al2H2
,”
J. Chem. Phys.
107
(
1
),
119
123
(
1997
).
103.
A. S.
Pozdeev
and
A. I.
Boldyrev
, “
Exploring the structure and bonding of group 13 homogeneous and heterogeneous hydrides with the X2H4 stoichiometry: a theoretical investigation
,”
Inorg. Chem.
62
(
20
),
8019
8026
(
2023
).
104.
E.
Osorio
,
J. K.
Olson
,
W.
Tiznado
, and
A. I.
Boldyrev
, “
Analysis of why boron avoids sp2 hybridization and classical structures in the BnHn+2 series
,”
Chem. – Eur. J.
18
(
31
),
9677
9681
(
2012
).
105.
B.
Ruščic
,
M.
Schwarz
, and
J.
Berkowitz
, “
Molecular structure and thermal stability of B2H4 and B2H+4 species
,”
J. Chem. Phys.
91
(
8
),
4576
4581
(
1989
).
106.
X.
Wang
,
L.
Andrews
,
S.
Tam
,
M. E.
DeRose
, and
M. E.
Fajardo
, “
Infrared spectra of aluminum hydrides in solid hydrogen: Al2H4 and Al2H6
,”
J. Am. Chem. Soc.
125
(
30
),
9218
9228
(
2003
).
107.
L.
Andrews
and
X.
Wang
, “
Infrared spectra of dialanes in solid hydrogen
,”
J. Phys. Chem. A
108
(
19
),
4202
4210
(
2004
).
108.
J. G.
Longenecker
,
A. M.
Mebel
, and
R. I.
Kaiser
, “
First infrared spectroscopic detection of the monobridged diboranyl radical (B2H5, C2v) and its D5-isotopomer in low-temperature diborane ices
,”
Inorg. Chem.
46
(
14
),
5739
5743
(
2007
).
109.
H.
Kawamura
,
V.
Kumar
,
Q.
Sun
, and
Y.
Kawazoe
, “
Cyclic and linear polymeric structures of AlnH3n (n =3–7) molecules
,”
Phys. Rev. A
67
(
6
),
063205
(
2003
).
110.
B.
Xu
,
J.
Liu
,
L.
Zhao
, and
L.
Yan
, “
Theoretical study on the structure and stability of aluminum hydride (AlnH3n) clusters
,”
J. Mater. Sci.
48
(
6
),
2647
2658
(
2013
).
111.
K.
Gandhi
,
D.
Kumar Dixit
, and
B.
Kumar Dixit
, “
Hydrogen desorption energies of aluminum hydride (AlnH3n) clusters
,”
Phys. B: Condens. Matter
405
(
15
),
3075
3081
(
2010
).

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