purpose. Firstly, it generates an additional inter-polaron attraction because the distant ions have small angle $\phi $. This additional attraction helps to overcome the direct Coulomb repulsion between polarons. And secondly, the Fröhlich EPI makes lattice (bi)polarons lighter. Here, following [@ale5; @alekor2; @jim2; @jim3], we consider a few examples of intersite superlight bipolarons.

Apex bipolarons
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High-$T_{c}$ oxides are doped charged-transfer ionic insulators with narrow electron bands. Therefore, the interaction between holes can be analyzed using computer simulation techniques based on a minimization of the ground state energy of an ionic insulator with two holes, the lattice deformations and the Coulomb repulsion fully taken into account, but neglecting the kinetic energy terms. Using these techniques net inter-site interactions of the in-plane oxygen hole with the $apex$ hole, Fig.1, and of two in-plane oxygen holes, Fig.2, were found to be attractive in $La_{2}CuO_{4}$ [@cat] with the binding energies $\Delta =119meV$ and $\Delta =60meV$, respectively. All other interactions were found to be repulsive.

Both apex and in-plane bipolarons can tunnel from one unit cell to another via the [* single*]{}-polaron tunnelling from one apex oxygen to its apex neighbor in case of the apex bipolaron [@ale5], Fig.1, or via the next-neighbor hopping 