Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modeling Single Molecule Junction Mechanics as a Probe of Interface
  Bonding   Using the atomic force microscope based break junction approach, applicable
to metal point contacts and single molecule junctions, measurements can be
repeated thousands of times resulting in rich data sets characterizing the
properties of an ensemble of nanoscale junction structures. This paper focuses
on the relationship between the measured force extension characteristics
including bond rupture and the properties of the interface bonds in the
junction. A set of exemplary model junction structures have been analyzed using
density functional theory based calculations to simulate the adiabatic
potential surface that governs the junction elongation. The junction structures
include representative molecules that bond to the electrodes through amine,
methylsulfide and pyridine links. The force extension characteristics are shown
to be most effectively analyzed in a scaled form with maximum sustainable force
and the distance between the force zero and force maximum as scale factors.
Widely used, two parameter models for chemical bond potential energy versus
bond length are found to be nearly identical in scaled form. Furthermore, they
fit well to the present calculations of N-Au and S-Au donor-acceptor bonds,
provided no other degrees of freedom are allowed to relax. Examination of the
reduced problem of a single interface, but including relaxation of atoms
proximal to the interface bond, shows that a single-bond potential form
renormalized by an effective harmonic potential in series fits well to the
calculated results. This allows relatively accurate extraction of the interface
bond energy. Analysis of full junction models show cooperative effects that go
beyond the series inclusion of the second bond in the junction, the spectator
bond that does not rupture.

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The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
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The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex