One of the most popular formats for storing chemical data is Structure-data file (SDF). It belongs to Chemical Table file (CT File) -collection of chemical formats. Another format in this family is tabular Molfile containing atoms and bonds. SDF is a combination of Molfile with optional additional compound data in a key-value form. These data can be molecular weight, Simplified Molecular Input Line Entry Specification (SMILES) or molecule identification numbers in different chemical bases.