What Are CTfile (Chemical Table File) and CTAB (Connection Table)?

CTfile (Chemical Table File) referes to six file formats that are used to store chemical information in a table style. All CTfile formats shares a common structure called CTAB (Connection Table), which describes the structural relationships and properties of a collection of atoms.

Below are short descriptions of CTfile formats:

• Molfile (Molecule File) - Describes a single molecular structure which can contain disjoint fragments. A Molfile is a 3-line header and CTAB structure.
• RGfile (Rgroup File) - Describes a single molecular query with Rgroups (Relationship Groups). Each RGfile is a combination of CTABs defining the root molecule and each member of each Rgroup in the query.
• rxnfile (Reaction File) - Contains the structural information for the reactants and products of a single reaction.
• SDfile (SDF - Structure Data File) - Contains structures and data for any number of molecules. A SDfile uses a Molfile and custom data to form a molecule structure. And multiple molecule structures are concatenated to support multiple molecules.
• RDfile (RDF - Reaction Data File) - Contains reactions as well as molecules, together with their associated data.
• XDfile (XML Data File) - XML-based data format for transferring recordsets of structure or reaction information with associated data.

CTfile formats have 2 versions: V3000 and V2000.

For detailed specifications, see "CTfile Formats" at download.accelrys.com/freeware/ctfile-formats/.

⇒ Convert SDF to SVG using Open Babel

⇐ SDF File Format Specification

⇑ Introduction to SDF/Mol File Format

⇑⇑ SDF/Mol File FAQ