  We present results of a study of small stoichiometric $Cd_{n}Te_{n}$
($1{\leq}n{\leq}6$) clusters and few medium sized non-stoichiometric
$Cd_{m}Te_{n}$ [($m,n= 13, 16, 19$); ($m{\neq}n$)] clusters using the Density
Functional formalism and projector augmented wave method within the generalized
gradient approximation. Structural properties
  {\it viz.} geometry, bond length, symmetry and electronic properties like
HOMO-LUMO gap, binding energy, ionization potential and nature of bonding {\it
etc.} have been analyzed. Medium sized non-stoichiometric clusters were
considered as fragments of the bulk with T{$_{d}$} symmetry. It was observed
that upon relaxation, the symmetry changes for the Cd rich clusters whereas the
Te rich clusters retain their symmetry. The Cd rich clusters develop a
HOMO-LUMO gap due to relaxation whereas there is no change in the HOMO-LUMO gap
of the Te rich clusters. Thus, the symmetry of a cluster seems to be an
important factor in determining the HOMO-LUMO gap.

Materials Science