By the semiempirical method in the intermediate coupling, the fine-structure parameters of 1sni Helium atom configurations were determined from the resolution of the system of nonlinear equations by the Newton’s iteration method. The system is based on an energy operator nondiagonal matrix, in which the following interactions were taken into account: the electrostatic, the spin-orbit (own and other) and the spin-spin interactions. With the obtained fine-structure parameters, the numerical diagonalization of the energy operator matrix was effected. The result was the calculated energies, coinciding to last digit with the experimental analogues, and the intermediate coupling coefficients. The gyromagnetic ratios of the 3I6 and 1I6 levels were determined and the appreciation of the character of the coupling in the consider systems was done. The Zeeman structure of the 1sni configurations was investigated. Its particularity and the domain of linearity of the magnetic field were determined. The gyromagnetic ratios