Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Stability and electronic structure of the complex K$_2$PtCl$_6$
  structure-type hydrides   The stability and bonding of the ternary complex K$_2$PtCl$_6$ structure
hydrides is discussed using first principles density functional calculations.
The cohesion is dominated by ionic contributions, but ligand field effects are
important, and are responsible for the 18-electron rule. Similarities to oxides
are discussed in terms of the electronic structure. However, phonon
calculations for Sr$_2$RuH$_6$ also show differences, particularly in the
polarizability of the RuH$_6$ octahedra. Nevertheless, the yet to be made
compounds Pb$_2$RuH$_6$ and Be$_2$FeH$_6$ are possible ferroelectrics. The
electronic structure and magnetic properties of the decomposition product,
FeBe$_2$ are reported. Implications of the results for H storage are discussed.

34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph