ASYMPTOTICS OF MANY-ELECTRON WAVE-FUNCTIONS AND CALCULATION OF TUNNEL TRANSITIONS

A new method for defining the wavefunction asymptotics for many-electron systems in the far-subbarrier region is suggested. The method is based on the Lippman-Schwinger formalism and can provide an accuracy in defining the asymptotics similar to that in the main region of the electron localization (MREL). The wavefunctions in MREL are the basis for obtaining the asymptotics. Molecular, cluster and surface systems are considered. A new approach to the calculation of tunneling transitions is formulated. A general expression for the tunneling current in scanning tunneling microscopy (STM) is obtained which strictly takes into account the penetration factor, the correlation between the tunneling current from individual atoms, and the angular dependence of asymptotics of basic atomic functions. This permits us to state and correctly solve the problem of defining the electron wavefunctions of the surface using the data of the tunneling current measurement at various biases and the positions of the tip.