One of the factors that limits the application of the single active electron (SAE) formalism to simulate the high harmonic generation (HHG) spectra of atoms and molecules using the time-dependent Schrödinger equation (TDSE) is the unknown model effective one-dimensional potential energy (V(x)) curve for the SAE. In the present contribution, we show that V(x) can be constructed from the one-dimensional molecular electrostatic potential (MEP) of the respective cation to access theoretical HHG spectra not only for simple atoms but also for multielectron complex molecules.