Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exact and approximate Kohn-Sham potentials in ensemble
  density-functional theory   We construct exact Kohn-Sham potentials for the ensemble density-functional
theory (EDFT) from the ground and excited states of helium. The
exchange-correlation (XC) potential is compared with the quasi-local-density
approximation and both single determinant and symmetry eigenstate
ghost-corrected exact exchange approximations. Symmetry eigenstate
Hartree-exchange recovers distinctive features of the exact XC potential and is
used to calculate the correlation potential. Unlike the exact case, excitation
energies calculated from these approximations depend on ensemble weight, and it
is shown that only the symmetry eigenstate method produces an ensemble
derivative discontinuity. Differences in asymptotic and near-ground-state
behavior of exact and approximate XC potentials are discussed in the context of
producing accurate optical gaps.

16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th