Table 1 Unit cell parameters determined from LeBail analysis of X-ray diffraction patterns for ThTi₂O₆ compositions, adopting the brannerite structure, targeting U⁵⁺ and U⁶⁺ incorporation with appropriate charge compensation, together with selected literature data. A weighted average cation radius (r_w) was calculated assuming nominal or reported compositions as appropriate, assuming U⁵⁺. R_wp and χ² goodness-of-fit metrics from the Le Bail analysis are also included. Sample identification reference (ID) refers to Fig. 1 and generally uses the nomenclature nEl, where n is the target U oxidation state and El is the charge compensating element (or otherwise refers to a literature reference).

(Th_0.90U_0.10)Ti₂O₆

0.1U

9.8133(3)

3.81475(8)

7.0226(2)

118.780(1)

230.420(10)

9.39

1.51

(Th_0.95U_0.05)Ti₂O₆

0.05U

9.8092(2)

3.81617(6)

7.0232(1)

118.786(1)

230.416(8)

9.77

1.57

(Th_0.85U_0.10Ca_0.05)Ti₂O₆

5Ca

9.8174(2)

3.80461(7)

7.0087(1)

118.775(1)

229.456(9)

12.88

1.20

(Th_0.90U_0.05Ca_0.05)Ti₂O₆

6Ca

9.8187(2)

3.81439(7)

7.0220(1)

118.801(1)

230.458(9)

13.60

1.20

(Th_0.80U_0.10Gd_0.10)Ti₂O₆

5Gd

9.8164(2)

3.79973(6)

7.0024(1)

118.765(1)

228.956(8)

9.66

1.07

(Th_0.85U_0.05Gd_0.10)Ti₂O₆

6Gd

9.8221(2)

3.80485(8)

7.0102(2)

118.789(1)

229.600(9)

11.32

1.08

(Th_0.95U_0.05)(Ti_1.95Al_0.05)O₆

5Al

9.8114(2)

3.81346(6)

7.0170(1)

118.835(1)

229.988(7)

10.93

1.07

(Th_0.95U_0.05)(Ti_1.90Al_0.10)O₆

6Al

9.8107(2)

3.81329(6)

7.0163(1)

118.834(1)

229.944(7)

10.65

1.07

(Th_0.95U_0.05)(Ti_1.95Cr_0.05)O₆

5Cr

9.8163(2)

3.81668(7)

7.0220(1)

118.824(1)

230.487(8)

11.03

1.05

(Th_0.95U_0.05)(Ti_1.9Cr_0.10)O₆

6Cr

9.8170(2)

3.81633(5)

7.0216(1)

118.837(1)

230.441(6)

10.40

1.07

ThTi₂O₆

²⁶

9.8140(2)

3.8228(1)

7.0313(2)

118.82(1)

231.12*

–

–

UTi₂O₆

⁸

9.8123(15)

3.7697(6)

6.9253(9)

118.957(6)

224.14*

–

–

(U_0.54Y_0.46)Ti₂O₆

²⁷

9.8039(2)

3.7188(1)

6.8403(2)

118.52(1)

219.12(1)

–

–

(U_0.74Ca_0.26)Ti₂O₆

¹¹

9.8008(2)

3.7276(1)

6.8745(1)

118.38(1)

220.97(1)

–

–

(U_0.50Tb_0.50)Ti₂O₆

¹²

9.808(2)

3.725(4)

6.871(9)

118.51*

220.6(1)

–

–

(U_0.50Dy_0.50)Ti₂O₆

¹²

9.810(2)

3.723(4)

6.857(8)

118.49*

220.1(1)

–

–

(U_0.49Y_0.51)Ti₂O₆

¹³

9.8086(6)

3.7179(3)

6.8418(5)

118.52(6)

219.2(1)

–

–