Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electronic structure and the glass transition in pnictide and
  chalcogenide semiconductor alloys. Part II: The intrinsic electronic midgap
  states   We propose a structural model that treats in a unified fashion both the
atomic motions and electronic excitations in quenched melts of pnictide and
chalcogenide semiconductors. In Part I (submitted to J. Chem. Phys.), we argued
these quenched melts represent aperiodic $pp\sigma$-networks that are highly
stable and, at the same time, structurally degenerate. These networks are
characterized by a continuous range of coordination. Here we present a
systematic way to classify these types of coordination in terms of discrete
coordination defects in a parent structure defined on a simple cubic lattice.
We identify the lowest energy coordination defects with the intrinsic midgap
electronic states in semiconductor glasses, which were argued earlier to cause
many of the unique optoelectronic anomalies in these materials. In addition,
these coordination defects are mobile and correspond to the transition state
configurations during the activated transport above the glass transition. The
presence of the coordination defects may account for the puzzling discrepancy
between the kinetic and thermodynamic fragility in chalcogenides. Finally, the
proposed model recovers as limiting cases several popular types of bonding
patterns proposed earlier, including: valence-alternation pairs, hypervalent
configurations, and homopolar bonds in heteropolar compounds.

22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin