Ab initio quality electron densities for large molecules can be generated by the combination of precalculated fragment densities stored in a database taking into account all of the short-range interactions within any predetermined envelope surrounding the fragment. For the effective usage of these databases, only a limited number of conformations of each fragment are stored and the electron densities for slightly distorted conformations are calculated by modifying the electron densities of the conformation stored. In this paper, we use two different nonlinear density transformation methods as well as a density matrix transformation method (DMT) to generate the distorted electron densities. The results of the nonlinear density transformations are then compared with direct calculations of the electron densities and with the DMT approximation of the electron densities, which uses a Lowdin transform and an inverse Lowdin transform of the electron density matrix.