CCL:G: cclib v1.5 released

On behalf of the cclib development team, we are pleased to announce the release of cclib 1.5, which is now available for download from This is a major update to version 1.4.1 that includes new functionality and attributes, as well as bug fixes and small improvements.

cclib is an open source library, written in Python, for parsing and interpreting the results of computational chemistry packages. It currently parses output files from 13 different programs: ADF, DALTON, Firefly, GAMESS (US), GAMESS-UK, Gaussian, Jaguar, Molpro, MOPAC, NWChem, ORCA, Psi and QChem.

Among other data, cclib extracts:

    * results of SCF, post-Hartree-Fock, TD-DFT and other calculations
    * coordinates, energies and geometry optimization data
    * information about atomic and molecular orbitals
    * vibrational modes, excited states and transitions
    * charges and electrostatic moments

(For a complete list see

cclib also provides some calculation methods for interpreting the electronic properties of molecules such as:

    * Mulliken and Lowdin population analyses
    * Overlap population analysis
    * Mayer's bond orders

(For a complete list see

For information on how to use cclib, see

If you need help, find a bug, want new features or have any questions, please send an email to our mailing list:

If your published work uses cclib, please support its development by citing the following article:
    N. M. O'Boyle, A. L. Tenderholt, K. M. Langner, cclib: a library for package-independent computational chemistry algorithms, J. Comp. Chem. 29 (5), 839-845 (2008)
You can also specifically reference this version of cclib as:
    Eric Berquist, Karol M. Langner, Noel M. O'Boyle, and Adam L. Tenderholt. Release of cclib version 1.5. 2016.

The cclib development team


Summary of changes since last version:
    Support for reading and writing CJSON files
    New parser: cclib now parses MOPAC files
    New attribute time for tracking coordinates in trajectories
    New attribute metadata for miscellaneous data not in other attributes