Properties of Bound Electron Pairs

The energies of spin singlet and triplet bound electron pairs are reckoned for electrons interacting through the Coulomb interaction, while sitting on neigbouring lattice sites. It is concluded that triplet pairs are unlikely to be observed due to screening. The interplay of inter-electron couplings of different spatial range is investigated. High-pressure induced superconductivity is analysed and qualitative agreement is achieved with observed results by working out the dependence of the critical temperature on the microscopic parameters, characterising the electron motion. This approach can be applied to other kinds of inter-electron interactions.