CIFLIB is a class library that was developed by the Nucleic Acid Database Project (NDB) to provide an application program interface (API) to macromolecular CIF (mmCIF) data. CIFLIB is designed to completely encapsulate all I/O operations and integrity checking on CIF dictionaries and data files from a calling application.


If you wish to install and use this software you should download the most up-to-date version from the above Web site. The links below are to copies which are suitable for browsing or for use if the primary Web site is not available. However, they may be out of date and lack the full functionality of the latest version.


CIFLIB is distributed from the Rutgers site of the Research Collaboratory for Structural Bioinformatics (RCSB) and forms an important component of the software systems used in the Protein Data Bank. Comments should be directed to

Language and platform

The software is written in C++ and C and should run on versions of Unix with suitable C++ compilers.


  • Installation: For Unix-type installations, copy the compressed tar file ciflib-v4-prod.tar.Z into an empty directory; uncompress and extract files using the Unix tar utility. Build the CIFLIB program using the make utility; run the test program for the class with 'make testclass'; run test programs for the function library with 'make test':
     cp ciflib-v4-prod.tar.Z /g/h/i; cd /g/h/i
    uncompress ciflib-v4-prod.tar.Z; tar xvf ciflib-v4-prod.tar
    cd ciflib-v4-prod
    make testclass
    make test
    If compress or tar are unavailable, individual source files may be saved to the build directory.
    For more details see the Installation Notes
  • CIFLIB C Language API Reference Guide ( HTML | PostScript | PDF format )
  • CIFLibCommon Reference Guide ( HTML | PostScript | PDF format )

Terms and conditions of use

Copyright in the software © Rutgers - The State University of New Jersey
Authors: John Westbrook, Shu-Hsin Hsieh and Olivera Tosic.

The software is distributed here under licence from the Protein Data Bank/RCSB. Use of the software is governed by the PDB software licence. Queries concerning any other use should be directed to


Westbrook, J. D., Hsieh, S.-H. & Fitzgerald, P. M. D. (1997). CIF applications. VI. CIFLIB: an application program interface to CIF dictionaries and data files. J. Appl. Cryst. 30, 79-83. [details]