The current molecular replacement programs are primarily implemented in reciprocal space. In this paper a new implementation in direct (real) space is proposed by matching the model atomic vectors with the vectors in the Patterson vector space using a six-dimensional exhaustive search method. It is shown that this implementation can find the correct rotations and translations of alpha helices in a myoglobin crystal structure using experimental diffraction data at 2 A resolution. A comparison with previous Patterson vector search methods is discussed.