Cationic and anionic composition-dependent mechanical and thermal properties of zinc-blende specimens under $${\hbox {Mg}}_{x} {\hbox {Zn}}_{1\hbox {-}x} {\hbox {S}}_{y} {\hbox {Se}}_{1\hbox {-}y}$$ Mg x Zn 1 - x S y Se 1 - y quaternary system: calculations with density functional FP-LAPW scheme

Elastic and thermal properties of zinc-blende $${\hbox {Mg}}_{x} {\hbox {Zn}}_{1\hbox {-}x} {\hbox {S}}_{y} {\hbox {Se}}_{1\hbox {-}y}$$ Mg x Zn 1 - x S y Se 1 - y quaternary alloys and their constituent binary/ternary compounds have been computed through first principles calculations. Elastic stiffness constants of specimens have been increased almost linearly with increasing sulfur composition at any fixed magnesium composition, while reverse trends have been observed with increasing magnesium composition at any fixed sulfur composition in each binary–ternary/ternary–quaternary system. Hardness of specimens has been increased almost linearly with increasing sulfur composition at any fixed magnesium composition, while it has been decreased with increasing magnesium composition at any fixed sulfur composition in each system. Mechanical stability, elastic anisotropy, compressibility, ductility and plasticity have been observed in each compound. Mixture of covalent and ionic bonding with prominent role of covalent nature, dominating role of bond bending over stretching and central nature of interatomic forces have been investigated in each compound. Interaction between the atoms in any compound has been observed to be anharmonic in nature via calculated Gruneisen parameter. Computed Debye temperature, Debye frequency, thermal conductivity and melting temperature of all the specimens have also been reported. Graphic Abstract