Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measures of Basicity in Silicate Minerals Revealed by Alkali Exchange
  Energetics   The energies of the alkali exchange reactions are computed from density
functional calculations for a series of alkali silicate minerals.
First-principles calculations are compared against (1) experiment; (2)
thermodynamic models; (3) calculations using empirical interatomic potentials
(with both polarizable shell model potentials and pairwise potentials with
partial charges); and (4) empirical correlations based on optical basicity and
Pauling bond strength. The first-principles calculations correlate well with
experimental values. The shell model potentials appear to account for Si-O-Si
versus Si-O oxygen basicity, but don't recover the differences in basicity
between Al-O-Si and Si-O-Si donors. The pair potentials don't even
qualitatively reproduce the reactivity trends established in the
first-principles calculations. Empirical correlations based on optical basicity
and Pauling bond strength successfully rank-order the exchange energies, but
fail to describe the large difference in basicity between Si-O-Si and Si-O
oxygen atoms. Knowing which models are capable of predicting ion exchange
energies in silicate minerals improves understanding of the physics of bonding
in ion-exchanged glasses.

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The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an