Atomic-scale methods and particularly MD can pro­vide a wide range of valuable information on the processes simulated. The most important are

1. Information on the physical state of the system.

This includes temperature and stress and their distribution; displacement of atoms and their transport; interaction energy and therefore force between defects; and evolution of internal, elastic, and free energies. Extraction of this information is well understood and procedures can be found in Chapter 1.04, Effect of Radiation on Strength and Ductility of Metals and Alloys;

Chapter 2.13, Properties and Characteristics of ZrC; Chapter 5.01, Corrosion and Compatibility and Chapter 1.09, Molecular Dynamics.

2. Detail of atomic mechanisms. This includes anal­ysis of the position and environment of individual atoms based on calculation of their energy, site stress, or local atomic configuration. Atoms can then be identified with particular features such as constituents of defect clusters, stacking faults, dis­location cores, and so on. Having this information at particular times provides unique knowledge of
defect structure, motion, interactions, and transformation.

The information summarized in 1 and 2 can be used to determine how the mechanisms involved depend on parameters such as obstacle type and size and dislocation type, material temperature, and applied stress or strain.