Atriums rhymes with:
aquariums, auditoriums, herbariums, honorariums, moratoriums, abiam's, aquariums, auditoriums, axioms, caladiums, condominiums, consortium's, geraniums, gymnasiums, herbariums, honorariums, idioms, mediums, millenniums, moratoriums, pentiums, petroleum's, podiums, premiums, stadium's, stadiums, symposiums, wiliams, zirconiums
Atriums sounds like:
adherence, adhering, adoring, adorning, adorns, adriance, attorney's, attorneys, attorneys', audiotronic, audiotronics, auditoriums, authoring