A study on a vertically correlated submonolayer (VCSML) InAs/GaAs quantum-dot (QD) heterostructure was presented. The Tagaki-Taupin equations were used to simulate the high resolution x-ray diffraction (HRXRD) (004) rocking curve. The simulation was achieved assuming that indium-rich VCSML QDs are embedded in a quantum well (QW) with lower indium content and an observed QD coverage of 10%.