The linear vibronic coupling in the system forms a trough on the adiabatic potential surface of the system, but D 5d and D 3d minima will be warped while co.

During recent decades, the vibronic coupling has already become one of the important issues incondensed matter physics because of its important physical properties and influence on differentphysical regions.

A new solution for coupled acoustic-electromagnetic equations is put forward.

Using the full-potential linear-muffin-tin-orbital programs and the linear-response linear-muffin-tin-orbital programs,we calculated the electronic band structure,phonon spectrum and electron-phonon coupling strength in MgB_2 film,and studied the effect of tension of MgB_2 film on its superconductivity.

The electron-phonon coupling intensity are studied by 2LO/LO.

Analyzing the electronic mass enhancement parameters obtained from the experimental data and the calculated electronic density of states,we deduced the electron-phonon coupling constants λ_ ep =1.

Using zone-center frozen phonon method, and considering the anharmonicity of phonon frequency , we calculate the phonon frequencies and electron-phonon coupling constant of B1g mode.

Using response-linearized linear muffin-tin orbital method we have studied the electronic band structure,phonon spectra,electron-phonon coupling and superconductivity of the new superconductor CaAlSi with AlB_2-type structure.