resonance integral, \(H_{\text{rs}}\)

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