Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electron--phonon interaction without overscreening: a strategy for
  first--principles modelling   State-of-the-art approaches to calculate the electron-phonon and the
phonon-electron self-energy are based on a mean-field approximation for the
interacting electronic system. This approach introduces an overscreening error
which results in an underestimation of the electron-phonon coupling strength.
We introduce a theoretical and numerical approach for the calculation of the
phonon-electron self-energy without the overscreening error. Starting from the
out-of-equilibrium Kadanoff-Baym equations for the phonon propagator, we
discuss and compare the ovescreened (i.e., symmetrically screened) and
overscreening--free (i.e., asymmetrically screened) cases. We point out that
the difficulty in treating the latter stems from the static approximation to
the dielectric function and from the need to obtain a self-energy that
preserves the elementary scattering processes. We solve both problems in the
equilibrium case by considering a manifestly symmetric form of the correct
self-energy which can be easily calculated numerically and yields an
overscreening--free coupling strength. Finally, we describe the numerical
implementation of this treatment into the first--principles Yambo code for the
calculations of phonon linewidths.

34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org