## resonance integral, $$H_{\text{rs}}$$

https://doi.org/10.1351/goldbook.R05337
In Hückel @M03996@ theory, the integral over space of the type $$\int \psi _{r}^{*}\ \hat{H}\ \psi _{s} \ \text{d}\tau$$ where $$\hat{H}$$ is the @H02730@ and $$\psi _{r}$$ and $$\psi _{s}$$ are different wavefunctions.
Source:
Green Book, 2nd ed., p. 17 [Terms] [Book]