The mathematical apparatus of the second quantization is
applied to the configuration interaction method. The configurations
are treated as a system of particles and holes against the vacuum
state built by the closed shell of the ground configuration. Expressions
for the operators of the basic physical quantities are
derived using the hole formalism generalized on an arbitrary
orthonormal system of orbitals. Rules for obtaining the result of
application of the operator 82 in the second quantization are
formulated. An application of Wick\u27s theorems for calculation of
the matrix elements over configurations leads to a simple logical
scheme of the configuration interaction method which is valid
for configurations of an arbitrary complexity and can be easily
programed for a computer
