“…RE 3+ S 2 crystallizes in two polytype structures: α-RES 2 (space group P2 1 /a, RE = La-Nd, Sm, Gd-Tm, Er) 8,10 and β-RES 2 (space group Pnma, RE = La-Nd). 15,18,20 Despite a significant number of studies on RE dichalcogenides, 25 specifically Eu compounds are poorly studied. To date, only two europium(II) dichalcogenides (Eu 2+ Se 2 and Eu 2+ Te 2 ) with a CuAl 2 structure type (space group I4/mcm) have been obtained and studied.…”