  It is argued that electron density dynamic's response to phonons at the
Brillouin zone boundary is the key factor in the superconductivity mechanism of
MgB2 as well as of all superconducting compounds leading to a real space
electron-hole pairing characterized by CP symmetry (Charge and Parity
symmetries) that enables a unified description of superconductivity
phenomenon.First principle calculation of the electron density difference is
determined by subtracting the electron density of the crystal distorted by
longitudinal acoustical phonons at the Brillouin zone boundary from that of the
perfect crystal.The origin of this electron density dynamic's response to this
kind of distortion that leads to in real space electron hole pairing
caracterized by CP symmetry is discussed in terms of local polarizabilities and
delocalized transfer of charge caused by phonon-distortion driven dynamical
change of orbital hybridization. This approach also provides clear and quick
guidelines in the search for a new superconductors.
