Chapter 18.7 The TNT refinement package

Crystallography of biological macromolecules

Second Online Edition (2012)

Part 18. Refinement

  1. D. E. Tronrud1,
  2. L. F. Ten Eyck2

Published Online: 14 APR 2012

DOI: 10.1107/97809553602060000861

International Tables for Crystallography

International Tables for Crystallography

How to Cite

Tronrud, D. E. and Ten Eyck, L. F. 2012. The TNT refinement package. International Tables for Crystallography. F:18:18.7:520–524.

Author Information

  1. 1

    Howard Hughes Medical Institute, Institute of Molecular Biology, 1229 University of Oregon, Eugene, OR 97403–1229, USA

  2. 2

    San Diego Supercomputer Center 0505, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093–0505, USA

Publication History

  1. Published Online: 14 APR 2012


The TNT refinement package was created in the late 1970s and its development continued for about 25 years. Its design included many features not present in its contemporaries and allowed for the testing and addition of many novel tools during its lifespan. These include the implementation of stereochemical restraints to molecules in other asymmetric units (both bonded and non-bonded), space-group-optimized fast Fourier transforms, which allowed rapid crystallographic calculations, and a quick and easy method to model the scattering of bulk solvent, which allowed the use of low-resolution data in refinement. TNT is no longer being developed by its original authors but its code has been included in Global Phasing, Ltd’s program Buster, where considerable improvements have been made.


  • macromolecular refinement;
  • preconditioned conjugate-gradient method;
  • bulk solvent scattering