  TiCoSb1+x (x=0.0, 0.01, 0.02, 0.03, 0.04, 0.06) samples have been
synthesized, employing solid state reaction method followed by arc menting.
Theoretical calculations, using Density Functional Theory (DFT) have been
performed to estimate band structure and density of states (DOS). Further,
energitic calculations, using first principle have been carried out to reveal
the formation energy for vacancy, interstitial, anti-site defects. Detail
structural calculation, employing Rietveld refinement reveals the presence of
embedded phases, vacancy and interstitial atom, which is also supported by the
theoretical calculations. Lattice strain, crystalline size and dislocation
density have been estimated by Williamson-Hall and modified Williamson-Hall
methods. Thermal variation of resistivity [\r{ho}(T)] and thermopower [S(T)]
have been explained using Mott equation and density of states (DOS)
modification near the Fermi surface due to Co vancancy and embedded phases.
Figure of merit (ZT) has been calculated and 4 to 5 times higher ZT for TiCoSb
than earlier reported value is obtained at room temperature.
