[en] The LUCIA calculation code intended for theoretical processing of experimental data on heavy ion elastic scattering is presented and described in detail. The algorithm used for calculation, code access and formation of initial data package are considered in detail. The code operation is illustrated by the results of calculations of the reaction ⁴⁰Ca+²⁰⁸Pb at energy 302 MeV and elastic scattering ⁶Li+¹²C at energy 90 MeV. The proposed code is especially adapted to work with very heavy colliding nuclei when one should take into account great values of orbital angular momentum (L<=500) and Coulomb parameter. The code can work with potentials of arbitrary form, is able to realize optimization up to ten independent parameters of optical potential, represents the results of calculations in a suitable for analysis graphic form. The code is written in FORTRAN for the BESM-6 computer