Electron-phonon interactions and reactivity in solids under high pressures and temperatures

The accurate non-perturbation simulations of electron-phonon interactions from finite differences have been developed using all-electron quantum solid-state chemistry. The simulations demonstrated that all electronic degeneracies couple specific vibrational motion, establishing the correlation of reactivity between crystal and electronic structures in solids under high pressures and temperatures. The electronic degeneracies around the Fermi level of the band structure are electronic reaction centers, strongly coupled to the atom motion associated with the specific vibrational mode. When the relevant vibrational motion removes these degeneracies in the band structure, the specific reaction mode is to be selected and then becomes extremely reactive. It means that a reaction can take place when the specific vibrational mode becomes reactive due to vibrationally mediated electron-electron interactions, resulting in immediately coupling of mechanical work to thermal heat. Therefore, such a reaction is a non-equilibrium process initiated by the specific reaction mode. The simulations have been validated in good agreement with several high-pressure experimental observations on chemical transformations in terms of both transition pressures and temperatures.