Virial theorem

The virial theorem is a feature of systems with central forces.

${\overline {T}}=-{\frac {1}{2}}{\overline {\sum _{i}{\frac {dU}{dr}}\cdot r_{i}}}$

where ${\overline {T}}$ is the kinetic energy. The overlines represent time averages. The right hand side is known as the virial of Clausius (Ref. 2).

References

1. Section 3.4 of Classical Mechanics by Herbert Goldstein 2nd Edition (1980) Addison Wesley
2. R. Clausius, " " Philosophical Magazine 40 pp. 122- (1870)