Strongly correlating liquids

Strongly correlating liquids are defined as those for whom $R\geq 0.9$ where (Eq. 6 ^[1])

R={\frac {\langle \Delta {\mathcal {V}}\Delta U\rangle }{\sqrt {\langle (\Delta {\mathcal {V}})^{2}\rangle \langle (\Delta U)^{2}\rangle }}}

where $\Delta U$ represents fluctuations of the potential in the NVT ensemble and ${\mathcal {V}}$ is the virial (see also Virial pressure).

Isomorphs

The liquid phase formed by the Lennard-Jones model is an example of a strongly correlating liquid^[3].