You need two free download programs: CHEMSKETCH and ARGUSLAB 1. Make a drawing of your target molecule with CHEMSKETCH and use Tools to both include hydrogens and to perform a 3-d optimization.Export this as a .mol file (CHEMSKETCH does not produce .pdb files). 2. Import the .mol file into ARGUSLAB and export as a .pdb file (there's nothing else to do in ARGUSLAB but it is useful for minimizing and producing various surface types eg ESP). 3. You can test the .pdb file with RASMOL and or DISCOVERY STUDIO VISUALIZER (both also free downloads and good for making nice pictures).
Rex Palmer Birkbeck College, London