Peptaibol Database (Popularity: ): Aims to provide a fully searchable database for the sequences of peptaibols. It deals primarily with naturally-occurring peptides, generally these have a fungal origin. Nucleic Acid Database (NDB) (Popularity: ): assembles and distributes structural information about nucleic acids. Inorganic Crystal Structure Database (ICSD) (Popularity: ): Contains records of all inorganic crystal structures, with atomic coordinates, published since 1913. The RCSB Protein Data Bank (PDB) (Popularity: ): Archive of experimentally-determined, biological macromolecule 3-D structures from the Brookhaven National Laboratory. Also includes newsletters and a description of the PDB file format. Metalloprotein Database and Browser (MDB) (Popularity: ): Contains quantitative information on all the metal-containing sites available from structures in the PDB distribution. Includes search and visualization interfaces. Metals Structure Database (CRYSTMET) (Popularity: ): A database of critically evaluated crystallographic data for metals, including alloys, intermetallics and minerals. Contains chemical, crystallographic and bibliographic data together with associated comments regarding experimental details for each study. Powder Diffraction File (PDF) (Popularity: ): maintained by the International Centre for Diffraction Data (ICDD) Crystallography Open Database (COD) (Popularity: ): A project accomodating crystal structure atomic coordinates prior to their publication. It is intended to give faster access to the latest structure determinations, openly. Heavy Atom Databank (HAD) (Popularity: ): Information on the preparation and characterisation of heavy-atom derivatives of protein crystals. Also contains information resulting from an analysis of the binding of these heavy-atoms with proteins in the crystal ... CSDSymmetry (Popularity: ): The most complete collation of observed molecular and crystallographic symmetry properties to date. A relational database built using Microsoft Access.