. 2021 Oct 28;48(12):44. doi: 10.1007/s00269-021-01167-1

Table 2.

Calorimetric entropy, S_cal, at 298.15 K of members of the OH-F and OH-Cl apatite binaries

OH-F apatite	X_F	S_cal J mol⁻¹ K⁻¹	OH-Cl apatite	X_Cl	S_cal J mol⁻¹ K⁻¹
OH–Ap	0.000	386.3	OH-Ap	0.000	386.3
APS92	0.298	384.0	APS94	0.150	390.4
APS91	0.390	384.8	APS93	0.185	390.8
APS77	0.400	384.0	APS80	0.352	391.9
APS70	0.440	383.6	APS71	0.497	393.4
APS85	0.440	385.7	APS74	0.538	394.3
APS69	0.470	383.8	APS73	0.645	395.5
APS84	0.570	383.3	APS72	0.735	396.1
APS86	0.610	384.1	APS78	0.817	399.6
APS68	0.639	383.9	APS82	0.814	399.9
APS87	0.670	384.2	APS83	0.871	399.0
APS95	0.718	384.2
APS96	0.759	384.6
F-Ap	0.999	383.2	Cl-Ap	0.998	400.6

X_F and X_Cl are calculated as F/(F + OH) and Cl/(Cl + OH), respectively. Data are plotted in Fig. 7. The 1σ-uncertainty of the S_cal data is ± 2.5 J mol⁻¹ K⁻¹