TY - JOUR AU - S. M. Tashpulatov AU - R. T. Parmanova TI - Structure of the essential spectrum and discrete spectrum of the energy operator of four-electron systems in the impurity Hubbard model. The third triplet state JO - Itogi nauki i tehniki. Sovremennaâ matematika i eë priloženiâ. Tematičeskie obzory PY - 2023 SP - 53 EP - 82 VL - 229 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/INTO_2023_229_a6/ LA - ru ID - INTO_2023_229_a6 ER -