Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Classical and ab initio preparation of reliable structures for polymeric
  coordination compounds   The detailed investigation of electronic and magnetic properties of polymeric
coordination materials with accurate ab initio quantum mechanical methods is
often computationally extremely demanding because of the large number of atoms
in the unit cell. Moreover, usually the available structural data are
insufficient or poorly determined, especially when the structure contains
hydrogen atoms. In order to be able to perform controlled ab initio
calculations on reliable structures, we use a two-step approach to
systematically prepare model structures for polymeric coordination compound
systems and to relax them to their equilibrium configuration. First, a
structure is constructed on the basis of a crystallographic database and
optimized by force field methods; in the second step, the structure is relaxed
by ab initio quantum mechanical molecular dynamics. With this structure, we
perform accurate electronic structure calculations. We will apply this
procedure to a Fe(II) triazole compound and to a coordination polymer of Cu(II)
ions with 2,5-bis(pyrazol-1-yl)-1,4-dihydroxybenzene.

20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph