Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Organic-Inorganic Hybrid CH3NH3PbI3 Perovskite Solar Cell Nanoclusters:
  Revealing Ultra-Strong Hydrogen Bonding and Mulliken Inner Complexes and
  Their Implication in Materials Design   Methylammonium lead iodide (CH3NH3PbI3) perovskite solar cell has produced a
remarkable breakthrough in the photovoltaic history of solar cell technology
because of its outstanding device based performance as a light-harvesting
semiconductor. Whereas the experimental and theoretical studies of this system
in the solid state have been numerously reported in the last 4 years, its
fundamental cluster physics is yet to be exploited. To this end, this study has
performed theoretical investigations using DFT-M06-2X/ADZP to examine the
principal geometrical, electronic, topological, and orbital properties of the
CH3NH3PbI3 nanocluster blocks. These clusters are found to be unusually
strongly bound, with binding energies lying between 93.53 and 125.11 kcal mol-1
(beyond the covalent limit, 40 kcal mol-1), enabling us to characterize the
underlying interactions as ultra-strong type. Based on this, together with the
unusually high charge transfers, strong hyperconjugative interactions,
sophisticated topologies of the charge density, and short intermolecular
distances uncovered, we have characterized the CH3NH3PbI3 as Mulliken inner
complexes. Additionally, the consequences of these, as well as of the
ultra-strong interactions, in designing novel functional nanomaterials are
briefly discussed. The various new results obtained in this study are not in
perfect agreement with those already reported experimentally (Nat. Commun.
2015, 6, 7124), and computationally (Chem. Commun., 2015, 51, 6434; Sci. Rep.
2016, doi:10.1038/srep21687; Chem. Mater. 2016, 28, 4259; J. Mat. Chem A 2016,
4, 4728; J. Phys. Chem. Lett. 2016, 7, 1596).

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The categories of this paper are: nucl-ex
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The categories of this paper are: math
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
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The categories of this paper are: stat
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The categories of this paper are: hep-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
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The categories of this paper are: hep-ex
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The categories of this paper are: q-bio
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
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The categories of this paper are: bayes-an