Material properties obtained by using the correlated function expansion for the quaternary alloy Ga_xIn_1-xP_yAs_1-y

The band gap and the bond length of the quaternary alloy Ga_{cursive Greek chi}In_{1-cursive Greek chi}P_yAs_1-y were estimated over the entire composition space by using a correlated function expansion (CFE) interpolation technique. The CFE band gap results reproduced well the experimental data for 35 samples of the alloy with an average error of 1.51 % and were compared with the results obtained by using other existing interpolation techniques. It was found that the CFE predictions were most accurate. In addition, the lattice-matching relations and the corresponding band gaps of the alloys with InP and GaAs substrates were determined. The CFE band gap variation of Ga_{cursive Greek chi}In_{1-cursive Greek chi}P_yAs_1-y lattice matched to InP was in good agreement with existing experimental data. This demonstrates that the CFE provides an efficient and accurate means to predict the material properties over the entire range of the alloy composition, thereby aiding in the discovery of new materials with desired material properties.