A suite of quinary thiohalides, ABa(2)MS(4)Cl (A = Rb, Cs; M = Ge, Sn), have been successfully synthesized. ABa(2)MS(4)Cl (A = Rb, Cs; M = Ge, Sn) undergoes an interesting structural transition from P2(1)/c (alpha phase) to I4/mcm (beta phase), which also leads to obvious disparities on the birefringence from 0.041 (alpha phase) to 0.094 (beta phase). Moreover, the result of deploying a real-space atom-cutting method on ABa(2)MS(4)Cl reveals that their (MS4)(4-) groups may take the major effect in terms of the anisotropy by a structural transition.