The growth of self-assembled semiconductor quantum dots (QDs) is driven by strain, induced by the mismatch of the lattice constants of the QD material (in this work, InAs) and that of the barrier material (GaAs). The resulting long-range strain field strongly modifies the energy diagram of the system, and has to be accounted for in realistic simulations of QD electronic properties. The nanoelectronic modeling tool NEMO-3D is designed to provide quantitative estimates of QD-bound electron and hole states by treating the system on the atomistic level. In this paper, a systematic study of the strain calculated within a domain consisting of up to 64 million atoms, followed by an electronic calculation on a subdomain containing up to 21 million atoms is presented. Unique and targeted eigenstates can be extracted from system matrices of order 4×10.