Using the first-principles densityfunctionalcalculations,thestructural,electronicandmagneticprop-<br />
erties oftheFe2XAl (X¼Cr,Mn,Ni)compoundsinboththeHg2CuTi andCu2MnAl-type structureswere<br />
studied bythefull-potentiallinearizedaugmentedplanewaves(FP-LAPW)method.Theexchangeand<br />
correlation potentialistreatedbythegeneralized-gradientapproximation(GGA)wheretheresultsshow<br />
that theCu2MnAl-type structureisenergeticallymorestablethantheHg2CuTi-type structureforthe<br />

The structural,electronic,magneticandelasticpropertiesoftheternarychalcogenidesKMnQ2 (Q¼O, S,<br />
Se, Te)crystalswereinvestigatedbymeansofspin-polarizeddensityfunctionaltheorycalculations.The<br />
3d orbitals oftheMnatomsweretreatedusingtheGGAþU approach.Thecalculatedequilibrium<br />
structural parametersagreewellwiththeexperimentaldata.Basedontheanalysisofthespin-polarized<br />
band structuresanddensityofstates,wepredictthehalf-metalliccharacterofthestudiedcompounds,<br />

The structural, electronic, elastic, thermoelectric and thermodynamic properties of NbMSb<br />
(M ¼ Fe, Ru, Os) half heusler compounds are reported. The full-potential linearized<br />
augmented plane wave (FP-LAPW) plus local orbital (lo) method, based on the density<br />
functional theory (DFT) was employed for the present study. The equilibrium lattice<br />
parameter results are in good compliance with the available experimental measurements.<br />