CML (.cml)

Background & Context

    • MIME type: chemical/x-cml
    • Chemical Markup Language, for interchange of chemical information.
    • Represents an arbitrary number of chemical compounds.
    • XML format.
    • Stores atomic coordinates, chemical bond information and metadata.

Import & Export

  • Import["file.cml"] imports a list of molecules from a CML file.
  • Export["file.cml",expr] exports a molecule or list of molecules to a CML file.
  • Import["file.cml",elem] imports the specified element from a CML file.
  • The import format can be specified with Import["file","CML"] or Import["file",{"CML",elem,}].
  • Export["file.cml",mol] creates a CML file from a molecule.
  • Export["file.cml",{mol1,mol2,}] creates a CML file from a list of molecules.
  • See the reference pages for full general information on Import and Export.
  • ImportString and ExportString support the CML format.

Import Elements

  • General Import elements:
  • "Elements"list of elements and options available in this file
    "Rules"full list of rules for each element and option
    "Options"list of rules for options, properties and settings
  • Data elements:
  • "Molecule"a symbolic representation of the molecule model
    "Molecule", na symbolic representation of the n^(th) molecule
    "Metadata"an Association containing the metadata from the file
    "Metadata", nthe metadata for the n^(th) molecule

Options

Examples

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Basic Examples  (2)

Show the Import elements available in a CML file:

Import all molecules from the file:

Import the second and fifth molecules from the file:

Import metainformation for the first compound in this file:

Export a molecule to a CML file:

Export Options  (2)

IncludeHydrogens  (1)

With the default setting of IncludeHydrogensAutomatic, hydrogen atoms are included in the output file if they are explicitly present in the molecule:

Specify that explicit hydrogens should be added before export:

"CoordinateDimension"  (1)

The option "CoordinateDimension" can take values of Automatic, 2 or 3.

Export a molecule to CML with two-dimensional coordinates:

Export a molecule to CML with three-dimensional coordinates:

Introduced in 2020
 (12.1)