Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Metastability Triggered Reactivity in Clusters at Realistic Conditions:
  A Case Study of N-doped (TiO$_2$)$_n$ for Photocatalysis   Here we report a strategy, by taking a prototypical model system for
photocatalysis (viz. N-doped (TiO$_2$)$_n$ clusters), to accurately determine
low energy metastable structures that can play a major role with enhanced
catalytic reactivity. Computational design of specific metastable photocatalyst
with enhanced activity is never been easy due to plenty of isomers on potential
energy surface. This requires fixing various parameters viz. (i) favorable
formation energy, (ii) low fundamental gap, (iii) low excitation energy and
(iv) high vertical electron affinity (VEA) and low vertical ionization
potential (VIP). We validate here by integrating several first principles based
methodologies that consideration of the global minimum structure alone can
severely underestimate the activity. As a first step, we have used a suite of
genetic algorithms [viz. searching clusters with conventional minimum total
energy ((GA)$_\textrm{E}$); searching clusters with specific property i.e. high
VEA ((GA)$_\textrm{P}^{\textrm{EA}}$), and low VIP
((GA)$_\textrm{P}^{\textrm{IP}}$)] to model the N-doped (TiO$_2$)$_n$ clusters.
Following this, we have identified its free energy using ab initio
thermodynamics to confirm that the metastable structures are not too far from
the global minima. By analyzing a large dataset, we find that N-substitution
((N)$_\textrm{O}$) prefers to reside at highly coordinated oxygen site to
maximize its coordination, whereas N-interstitial ((NO)$_\textrm{O}$) and
split-interstitial ((N$_2)_\textrm{O}$) favor the dangling oxygen site.
Interestingly, we notice that each types of defect (viz. substitution,
interstitials) reduce the fundamental gap and excitation energy substantially.
However, (NO)$_\textrm{O}$ and (N$_2)_\textrm{O}$ doped clusters are the
potential candidates for overall water splitting, whereas N$_\textrm{O}$ is
congenial only for oxygen evolution reaction.

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The categories of this paper are: nucl-th
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The categories of this paper are: comp-gas
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The categories of this paper are: cmp-lg
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The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: adap-org
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The categories of this paper are: math
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The categories of this paper are: quant-ph
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The categories of this paper are: q-bio
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The categories of this paper are: nlin