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Three new NaBa2M3Q3(Q2) (M = Ag, Cu; Q = S, Se) chalcogenides were prepared using solid-state methods and structurally characterized using single-crystal X-ray diffraction. NaBa2Ag3Se3(Se2) and NaBa2Cu3Se3(Se2) crystallize in the monoclinic C2/m space group and have a two-dimensional structure composed of edge-sharing MSe4/4 tetrahedra separated by Na+ and Ba2+ cations, along with (Se2)2- dimers at the center of the spacings between [M3Se3]3- slabs. NaBa2Ag3S3(S2) adopts a related structure with the C2/m space group but has additional, crystallographically distinct Ag atoms in the [Ag3S3]3- layer that are linearly coordinated. NaBa2Ag3Se3(Se2) and NaBa2Ag3S3(S2) have indirect band gaps measured to be 1.2 eV and 1.9 eV, respectively, which is supported by band structures calculated using density functional theory. Mixed- anion NaBa2Cu3Se5-xSx compositions were prepared to probe for the presence of anion ordering and heteronuclear (S-Se)2- dimers. Structural analyses of the sulfoselenides indicate selenium preferentially occupies the Q-Q dimer sites, while Raman spectroscopy reveals a mixture of (S2), (Se2), and heteronuclear (S-Se) units in the sulfur-rich products. The local ordering of the chalcogens is rationalized using simple bonding concepts and adds to a growing framework for understanding ordering phenomena in mixed-anion systems.