. "fine structure"@en-us . . "111457586"^^ . . "11457586-n"^^ . "110718106"@en-us . . "0"^^ . . . "0"^^ . . "fine structure"^^ . . . "the presence of groups of closely spaced spectrum lines observed in the atomic spectrum of certain elements; \"the fine structure results from slightly different energy levels\""@en-us . .