A Method of Calculation of Electrical Conductivity

A new method of calculating electrical conductivity is presented. The method is based upon the theory of relaxation function or after-effect function, from which the general formula for the electrical conductivity is obtained. Taking into account a time required for an observation, we introduce the irreversibility into the theory and investigate the relaxation behaviour of the process, by which the electrical conductivity is calculated and the practical expression is obtained. In the perturbation approximation the result is the same as the expression obtained on the basis of the Bloch theory.