  The structural, electronic and vibrational properties of atomic wires
composed of the early alkali metals lithium and sodium are studied using
density functional perturbation theory. The s-like electronic states near the
Fermi level couple very weakly to longitudinal acoustic phonons and not at all
to the transverse acoustic phonons, which results in a weak overall
electron-phonon coupling. The results are compared to earlier studies on the
electron-phonon coupling in metallic atomic wires and reinforces the idea that
s-like states at the Fermi level give rise to weak electron-phonon coupling in
one-dimension, in contrast with materials containing d-like states at the Fermi
level which have correspondingly larger electron-phonon coupling due to
interactions with transverse phonons.
