Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Finite elements and the discrete variable representation in
  nonequilibrium Green's function calculations. Atomic and molecular models   In this contribution, we discuss the finite-element discrete variable
representation (FE-DVR) of the nonequilibrium Green's function and its
implications on the description of strongly inhomogeneous quantum systems. In
detail, we show that the complementary features of FEs and the DVR allows for a
notably more efficient solution of the two-time Schwinger/Keldysh/Kadanoff-Baym
equations compared to a general basis approach. Particularly, the use of the
FE-DVR leads to an essential speedup in computing the self-energies.
  As atomic and molecular examples we consider the He atom and the linear
version of H$_3^+$ in one spatial dimension. For these closed-shell models we,
in Hartree-Fock and second Born approximation, compute the ground-state
properties and compare with the exact findings obtained from the solution of
the few-particle time-dependent Schr\"odinger equation.

23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph