  Intriguing properties of the misfit layered chalcogenide
(LaS)$_{1.196}$VS$_2$ crystals were investigated by transport, optical
measurements, angle-resolved photoemission (ARPES) and x-ray diffraction.
Although no clear anomaly is found in transport properties as a function of
temperature, a large spectral weight transfer, up to at least 1 eV, is observed
by both optical and photoemission spectroscopies. ARPES reveals that a nearly
filled band with negative curvature, close enough from the Fermi level at 300K
to produce metallic-like behaviour as observed in optical conductivity spectra.
At low temperature, the band structure is strongly modified, yielding to an
insulating state with a optical gap of 120 meV. An accurate (3+1)D analysis of
x-ray diffraction data shows that, although a phase transition does not occur,
structural distortions increase as temperature is decreased, and vanadium
clusterization is enhanced. We found that the changes of electronic properties
and structure are intimately related. This indicates that structural distorsion
play a major role in the insulating nature of (LaS)$_{1.196}$VS$_2$ and that
electronic correlation may not be important, contrary to previous belief. These
results shed a new light on the mechanism at the origin of non-linear electric
properties observed in (LaS)$_{1.196}$VS$_2$.
