Calculated formation energies for the (Eu, Tb)-codoped Ca₁₀(PO₄)₆F₂ with different model structures and Ca vacancy defects.

Systems	Structures	Formation energy (eV)
(Eu, Tb)-codoped Ca10(PO4)6F2	Str. 1	3.77
	Str. 2	3.53
	Str. 3	3.16
	Str. 4	3.15
	Str. 5	1.19
	Str. 6	1.10
(Eu, Tb)-codoped Ca10(PO4)6F2 with VCa	Str. 7	1.64
	Str. 8	2.64
	Str. 9	1.27