We discuss how to define and to compute internal forces in a molecule subjected to mechanical stress. Because of the inherently many-body character of intramolecular interactions, internal forces cannot be uniquely defined without specifying a set of internal coordinates used to describe the molecular structure. When such a set is comprised of 3N − 6 interactomic distances (N being the number of atoms) and includes the bond lengths of interest, we show that the associated forces, while satisfying the equation F = ∂V/∂R (where R is the bond length, F is the internal force in this bond, and V is the potential energy of the molecule), can be determined from the molecular geometry alone. We illustrate these ideas using several toy models ranging from small molecules to a graphene sheet and show that the magnitude of the internal force in a bond is not necessarily a good predictor of its strength in response to mechanical loading. At the same time, analysis of internal forces reveals interesting phenomena such as the force multiplication effect, where weak external forces may, e.g., be used to break strong bonds, and offers insight into the catch-bond phenomenon where chemical reactivity is suppressed through application of a force.

1.
M. K.
Beyer
and
H.
Clausen-Schaumann
,
Chem. Rev.
105
(
8
),
2921
2948
(
2005
).
2.
C. R.
Hickenboth
,
J. S.
Moore
,
S. R.
White
,
N. R.
Sottos
,
J.
Baudry
, and
S. R.
Wilson
,
Nature (London)
446
(
7134
),
423
427
(
2007
).
3.
M. M.
Caruso
,
D. A.
Davis
,
Q.
Shen
,
S. A.
Odom
,
N. R.
Sottos
,
S. R.
White
, and
J. S.
Moore
,
Chem. Rev.
109
(
11
),
5755
5798
(
2009
).
4.
A. L.
Black
,
J. M.
Lenhardt
, and
S. L.
Craig
,
J. Mater. Chem.
21
,
1655
1663
(
2011
).
5.
P.
Dopieralski
,
P.
Anjukandi
,
M.
Ruckert
,
M.
Shiga
,
J.
Ribas-Arino
, and
D.
Marx
,
J. Mater. Chem.
21
(
23
),
8309
8316
(
2011
).
6.
R.
Boulatov
,
Pure Appl. Chem.
83
(
1
),
25
41
(
2011
).
7.
Z.
Huang
and
R.
Boulatov
,
Chem. Soc. Rev.
40
(
5
),
2359
2384
(
2011
).
8.
M. J.
Kryger
,
A. M.
Munaretto
, and
J. S.
Moore
,
J. Am. Chem. Soc.
133
,
18992
18998
(
2011
).
9.
J.
Ribas-Arino
and
D.
Marx
,
Chem. Rev.
112
(
10
),
5412
5487
(
2012
).
10.
D. E.
Makarov
,
J. Chem. Phys.
135
(
19
),
194112
(
2011
).
11.
D. E.
Makarov
, in
Single-Molecule Studies of Proteins
, edited by
A.
Oberhauser
(
Springer
,
2012
), pp.
235
268
.
12.
T. J.
Kucharski
and
R.
Boulatov
,
J. Mater. Chem.
21
(
23
),
8237
8255
(
2011
).
13.
D. A.
Davis
,
A.
Hamilton
,
J.
Yang
,
L. D.
Cremar
,
G. D.
Van
,
S. L.
Potisek
,
M. T.
Ong
,
P. V.
Braun
,
T. J.
Martinez
,
S. R.
White
,
J. S.
Moore
, and
N. R.
Sottos
,
Nature (London)
459
,
68
72
(
2009
).
14.
J.
Ribas-Arino
,
M.
Shiga
, and
D.
Marx
,
Angew. Chem., Int. Ed.
48
(
23
),
4190
4193
(
2009
).
15.
J. M.
Lenhardt
,
M. T.
Ong
,
R.
Choe
,
C. R.
Evenhuis
,
T. J.
Martinez
, and
S. L.
Craig
,
Science
329
(
5995
),
1057
1060
(
2010
).
16.
G. S.
Kochhar
,
A.
Bailey
, and
N. J.
Mosey
,
Angew. Chem., Int. Ed.
49
(
41
),
7452
7455
(
2010
).
17.
J. N.
Brantley
,
K. M.
Wiggins
, and
C. W.
Bielawski
,
Polym. Int.
62
,
2
(
2013
).
18.
J. N.
Brantley
,
K. M.
Wiggins
, and
C. W.
Bielawski
,
Angew. Chem.
52
(
14
),
3806
3808
(
2013
).
19.
J. N.
Brantley
,
S. S. M.
Konda
,
D. E.
Makarov
, and
C. W.
Bielawski
,
J. Am. Chem. Soc.
134
(
24
),
9882
9885
(
2012
).
20.
H. S.
Smalo
and
E.
Uggerud
,
Mol. Phys.
111
(
9–11
),
1563
1573
(
2013
).
21.
W.
Li
,
S. A.
Edwards
,
L.
Lu
,
T.
Kubar
,
S. P.
Patil
,
H.
Grubmuller
,
G.
Groenhof
, and
F.
Grater
,
ChemPhysChem
14
(
12
),
2687
2697
(
2013
).
22.
B. I.
Costescu
and
F.
Grater
,
BMC Biophys.
6
,
5
(
2013
).
23.
W.
Stacklies
,
C.
Seifert
, and
F.
Graeter
,
BMC Bioinf.
12
,
101
(
2011
).
24.
T.
Stauch
and
A.
Dreuw
,
J. Chem. Phys.
140
(
13
),
134107
(
2014
).
25.
R.
Boulatov
,
Nat. Chem.
5
(
2
),
84
86
(
2013
).
26.
M. B.
Larsen
and
A. J.
Boydston
,
J. Am. Chem. Soc.
135
(
22
),
8189
8192
(
2013
).
27.
M. B.
Larsen
and
A. J.
Boydston
,
J. Am. Chem. Soc.
136
(
4
),
1276
1279
(
2014
).
28.
H. M.
Klukovich
,
T. B.
Kouznetsova
,
Z. S.
Kean
,
J. M.
Lenhardt
, and
S. L.
Craig
,
Nat. Chem.
5
(
2
),
110
114
(
2013
).
29.
S. S. M.
Konda
,
J. N.
Brantley
,
B. T.
Varghese
,
K. M.
Wiggins
,
C. W.
Bielawski
, and
D. E.
Makarov
,
J. Am. Chem. Soc.
135
(
34
),
12722
12729
(
2013
).
30.
R.
Groote
,
B. M.
Szyja
,
F. A.
Leibfarth
,
C. J.
Hawker
,
N. L.
Doltsinis
, and
R. P.
Sijbesma
,
Macromolecules
47
(
3
),
1187
1192
(
2014
).
31.
E.
Evans
and
K.
Ritchie
,
Biophys. J.
76
,
2439
(
1999
).
32.
E.
Evans
and
K.
Ritchie
,
Biophys. J.
72
,
1541
1555
(
1997
).
33.
M. K.
Beyer
,
J. Chem. Phys.
112
(
17
),
7307
7312
(
2000
).
34.
S.
Kirmizialtin
,
L.
Huang
, and
D. E.
Makarov
,
J. Chem. Phys.
122
,
234915
(
2005
).
35.
P.-C.
Li
and
D. E.
Makarov
,
J. Chem. Phys.
119
,
9260
(
2003
).
36.
O. K.
Dudko
,
G.
Hummer
, and
A.
Szabo
,
Proc. Natl. Acad. Sci. U.S.A.
105
(
41
),
15755
15760
(
2008
).
37.
Y.
Suzuki
and
O. K.
Dudko
,
J. Chem. Phys.
134
(
6
),
065102
(
2011
).
38.
Y.
Suzuki
and
O. K.
Dudko
,
Phys. Rev. Lett.
104
(
4
),
048101
(
2010
).
39.
S. S. M.
Konda
,
J. N.
Brantley
,
C. W.
Bielawski
, and
D. E.
Makarov
,
J. Chem. Phys.
135
,
164103
(
2011
).
40.
S. S. M.
Konda
,
S. M.
Avdoshenko
, and
D. E.
Makarov
,
J. Chem. Phys.
140
(
10
),
104114
(
2014
).
41.
L. D.
Landau
and
E. M.
Lifshitz
,
Mechanics
(
Butterworth-Heinenann
,
1976
).
42.
M. S.
Gordon
and
J. A.
Pople
,
J. Chem. Phys.
49
(
10
),
4643
(
1968
).
43.
P.
Pulay
,
G.
Fogarasi
,
F.
Pang
, and
J. E.
Boggs
,
J. Am. Chem. Soc.
101
(
10
),
2550
2560
(
1979
).
44.
C. Y.
Peng
,
P. Y.
Ayala
,
H. B.
Schlegel
, and
M. J.
Frisch
,
J. Comput. Chem.
17
(
1
),
49
56
(
1996
).
45.
O. K.
Dudko
,
G.
Hummer
, and
A.
Szabo
,
Phys. Rev. Lett.
96
(
10
),
108101
(
2006
).
46.
H.
Eyring
,
J. Chem. Phys.
3
,
107
(
1935
).
47.
S. N.
Zhurkov
,
Int. J. Fract. Mech.
1
(
4
),
311
322
(
1965
).
48.
49.
M. G.
Saunders
and
G. A.
Voth
,
Annu. Rev. Biophys.
42
,
73
93
(
2013
).
50.
W. G.
Noid
,
J. Chem. Phys.
139
(
9
),
090901
(
2013
).
51.
A.
Carpinteri
,
Structural Mechanics: A Unified Approach
(
Taylor and Francis
,
1997
).
52.
C. J. F. R. S.
Maxwell
,
Philos. Mag.
27
(
182
),
294
299
(
1864
).
53.
A.
Bailey
and
N. J.
Mosey
,
J. Chem. Phys.
136
,
044102
(
2012
).
54.
Z.
Huang
and
R.
Boulatov
,
Pure Appl. Chem.
82
(
4
),
931
951
(
2010
).
55.
B. J.
McCall
,
T. R.
Geballe
,
K. H.
Hinkle
, and
T.
Oka
,
Science
279
(
5358
),
1910
1913
(
1998
).
56.
F.
Neese
,
Wiley Interdiscip. Rev.: Comput. Mol. Sci.
2
(
1
),
73
78
(
2012
).
57.
See supplementary material at http://dx.doi.org/10.1063/1.4896944 for additional tests and illustrations.
58.
D. J.
Jacobs
and
M. F.
Thorpe
,
Phys. Rev. Lett.
75
(
22
),
4051
4054
(
1995
).
59.
K. S.
Novoselov
,
A. K.
Geim
,
S. V.
Morozov
,
D.
Jiang
,
Y.
Zhang
,
S. V.
Dubonos
,
I. V.
Grigorieva
, and
A. A.
Firsov
,
Science
306
(
5696
),
666
669
(
2004
).
60.
L. D.
Landau
and
E. M.
Lifshitz
,
Theory of Elasticity
(
Pergamon Press Ltd
,
London
,
1959
).
61.
A. J.
Rader
,
B. M.
Hespenheide
,
L. A.
Kuhn
, and
M. F.
Thorpe
,
Proc. Natl. Acad. Sci. U.S.A.
99
(
6
),
3540
3545
(
2002
).
62.
T.
Mamonova
,
B.
Hespenheide
,
R.
Straub
,
M. F.
Thorpe
, and
M.
Kurnikova
,
Phys. Biol.
2
(
4
),
S137
S147
(
2005
).

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