Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Case study of Rb+(aq), quasi-chemical theory of ion hydration, and the
  no split occupancies rule   Quasi-chemical theory applied to ion hydration combines statistical
mechanical theory, electronic structure calculations, and molecular simulation,
disciplines which are individually subjects for specialized professional
attention. Because it combines activities which are themselves non-trivial,
quasi-chemical theory is typically viewed with surprise. Nevertheless, it
provides a fully-considered framework for analysis of ion hydration.
Furthermore, the initial calculations are indeed simple, successful, and
provide new information to long-standing experimental activities such as
neutron diffraction by hydrated ions. Here we review quasi-chemical theory in
the context of a challenging application, Rb+(aq).

18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org