Calculate 3d coordinates using distance geometry

Distance geometry (DG) is quick method but produces results of not the best quality. Advantage of distance geometry is that it will always generate 3D structure, but often the structure is not perfect, e.g. aromatic structures are not flat. when although it may have atom clashes. Usually distance geometry is followed by molecular mechanics optimization. Original DB book is available. Some references to modified DG :
http://pubs.acs.org/doi/abs/10.1021/ci0340557;
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC138530/
Earlier modified DG is described in http://pubs.acs.org/doi/abs/10.1021/ci00011a015