Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Signatures of Discontinuity in the Exchange-Correlation Energy
  Functional Derived from the Subband Electronic Structure of Semiconductor
  Quantum Wells   The discontinuous character of the exact exchange-correlation $(xc)$ energy
functional of Density Functional Theory is shown to arise naturally in the
subband spectra of semiconductor quantum wells. Using an \emph{ab-initio} $xc$
functional, including exchange exactly and correlation in an exact partial way,
a discontinuity appears in the $xc$ potential, each time a subband becomes
slightly occupied. Exchange and correlation give opposite contributions to the
discontinuity, with correlation overcoming exchange. The jump in the
intersubband energy is in excellent agreement with experimental data.

37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph