The　Pb4Sb12-xBi8+xSe34　(x　=　0,　1,　2,　3,　4,　and　5)　crystals　belong　to　pavonite　homologues　composed　of　thick　NaCl-　and　thin　GeS-type　slabs　which　crystallize　in　the　C2/m　space　group.　Pb4Sb12-xBi8+xSe34　compounds　exhibit　n-type　semiconductor　transport　behavior　and　demonstrate　excellent　thermodynamic　stability.　These　intrinsic　compounds　have　high　carrier　concentrations　of　∼2.18　×　1019　to　4.47　×　1020　cm-3,　leading　to　high　electrical　conductivities.　The　two-band　electronic　structure　results　in　a　high　Seebeck　coefficient.　Taking　Pb4Sb9Bi11Se34　as　an　example,　it　has　a　remarkable　Seebeck　coefficient　of　−149.1　μV　K-1　and　high　electrical　conductivity　of　∼118　S　cm-1.　It　is　comparable　with　other　pavonite　at　723　K.　On　the　other　hand,　due　to　mixed　occupancies　of　cation　sites　and　complex　crystal　structure,　the　Pb4Sb9Bi11Se34　features　ultralow　lattice　thermal　conductivity　of　∼0.25　W　m-1　K-1　at　723　K.　The　high　figure　of　merit,　ZT,　of　0.48　for　Pb4Sb9Bi11Se34　is　obtained　at　723　K.　©　2024　American　Chemical　Society.