The matrix of the energy operator is constructed for the nsn'g and nsn'h configurations. The electrostatic, spin-own-orbit, spin-other-orbit, spin-spin, and orbit-orbit interactions are taken into account. The fine-structure parameters, the coupling coefficients, and the gyromagnetic ratios are calculated for the 1sng (n = 5-9) and 1s7h configurations of a helium atom. Discrepancies between the calculated and experimental energy values are virtually zero.