Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Matrix mechanics for actual atoms and molecules   Matrix mechanics is developed to describe the bound state spectra in few- and
many-electron atoms, ions and molecules. Our method is based on the matrix
factorization of many-electron (or many-particle) Coulomb Hamiltonians which
are written in hyperspherical coordinates. As follows from the results of our
study the bound state spectra of many-electron (or many-particle) Coulomb
Hamiltonians always have the `ladder' structure and this fundamental fact can
be used to determine and investigate the bound states in various few- and
many-body Coulomb systems.

16
The categories of this paper are: stat
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio