A number of real-space torsion-angle refinement techniques for proteins, nucleic acids, ligands and solvent.

This paper describes the implementation of real-space torsion-angle refinement as a tool for model (re)building. The algorithmic details and parameterization for a number of different protocols are presented, as well as the handling of special conditions. Examples illustrating the use of the algorithms show that these tools provide a great advantage over traditional methods for building macromolecular structures. All these algorithms have been implemented in QUANTA (MSI), currently available as version QUANTA98.