Atomistic Simulation of Intrinsic Defects and Trivalent and Tetravalent Ion Doping in Hydroxyapatite

Table 6

Solution energies (eV) for substitution of the rare earth (M³⁺ = Tm, Er, Ho, Dy, Tb, and Gd) ions in HAP.

Mechanisms		Dopant
		Tm^3+	Er^3+	Ho^3+	Dy^3+	Tb^3+	Gd^3+
Equation (1)		3.06	2.91	2.85	2.81	2.60	2.72
		3.31	3.31	3.05	2.99	2.74	1.56
Equation (2)		2.17	2.17	1.97	1.93	1.71	1.80
		3.31	3.31	3.05	2.99	2.74	1.56
Equation (3)		4.78	4.59	4.52	4.47	4.20	4.35
		5.09	2.99	4.77	4.70	4.38	2.90
Equation (4)		2.65	2.54	2.50	2.47	2.31	2.40
		2.84	1.58	2.65	2.61	2.42	1.52
Equation (5)		8.90	8.69	8.98	8.78	8.55	8.90
Equation (6)		8.30	8.07	8.36	8.17	7.93	8.29
Equation (7)		18.03	17.76	18.11	17.87	17.60	18.02
		11.55	11.30	11.62	11.39	11.11	11.54