【答案】应助回帖
★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ 感谢参与,应助指数 +1 liliangfang: 金币+2, 应助指数+1, 多谢帮助 2012-06-18 08:14:47 wuguohao111: 金币+20, ★★★★★ 最佳答案 2012-06-18 09:38:14
结构一:引用回帖: *data for ICSD #1950
Coll Code 1950
Rec Date 1980/01/01
Mod Date 2003/04/01
Chem Name Dilanthanum Dititanate
Structured La2 (Ti2 O7)
Sum La2 O7 Ti2
ANX A2B2X7
D(calc) 5.79
Title Dititanate de lanthane
Author(s) Gasperin, M.
Reference Acta Crystallographica B (24,1968-38,1982)
(1975), 31, 2129-2130
Phase Transition
(1992), 38, 127-220
Unit Cell 7.800(3) 13.011(4) 5.546(2) 90. 90. 98.60(2)
Vol 556.51
Z 4
Space Group P 1 1 21
SG Number 4
Cryst Sys monoclinic
Pearson mP44
Wyckoff a22
R Value .075
Red Cell P 5.546 7.8 13.011 98.6 90 90 556.512
Trans Red 0.000 0.000 1.000 / 1.000 0.000 0.000 / 0.000 1.000 0.000
Comments Stable up to 1770 K (2nd ref., Tomaszewski)
The structure has been assigned a PDF number: 28-517
At least one temperature factor is implausible or
meaningless but agrees with the value given in the paper.
Atom # OX SITE x y z SOF H ITF(B)
La 1 +3 2 a 0.2789(3) 0.1138(2) 0.25 1. 0 0.4(2)
La 2 +3 2 a 0.7741(3) 0.0993(2) 0.2543(6) 1. 0 0.5(2)
La 3 +3 2 a 0.3502(3) 0.3909(2) 0.8026(6) 1. 0 0.4(2)
La 4 +3 2 a 0.8525(3) 0.4164(2) 0.8413(6) 1. 0 0.4(2)
Ti 1 +4 2 a 0.0320(9) 0.1191(5) 0.7630(16) 1. 0 0.3(2)
Ti 2 +4 2 a 0.5271(9) 0.1200(5) 0.7598(16) 1. 0 0.3(2)
Ti 3 +4 2 a 0.0780(9) 0.3228(5) 0.2946(15) 1. 0 0.5(2)
Ti 4 +4 2 a 0.5833(9) 0.3263(5) 0.2975(15) 1. 0 0.5(2)
O 1 -2 2 a 0.776(3) 0.109(2) 0.799(5) 1. 0 0.4(2)
O 2 -2 2 a 0.275(4) 0.090(2) 0.698(5) 1. 0 0.8(2)
O 3 -2 2 a 0.030(3) 0.016(2) 0.024(6) 1. 0 0.5(2)
O 4 -2 2 a 0.479(3) 0.020(2) 0.026(5) 1. 0 0.5(2)
O 5 -2 2 a 0.098(3) 0.226(2) 0.969(6) 1. 0 0.7(2)
O 6 -2 2 a 0.517(3) 0.229(2) 0.963(5) 1. 0 0.5(2)
O 7 -2 2 a 0.033(3) 0.187(2) 0.460(5) 1. 0 0.5(2)
O 8 -2 2 a 0.559(3) 0.189(2) 0.455(5) 1. 0 0.5(2)
O 9 -2 2 a 0.089(4) 0.409(2) 0.554(3) 1. 0 0.4(2)
O 10 -2 2 a 0.613(4) 0.398(2) 0.569(6) 1. 0 0.7(2)
O 11 -2 2 a 0.121(3) 0.432(2) 0.078(5) 1. 0 0.4(2)
O 12 -2 2 a 0.599(3) 0.440(2) 0.089(5) 1. 0 0.3(2)
O 13 -2 2 a 0.327(3) 0.312(1) 0.323(4) 1. 0 0.1(2)
O 14 -2 2 a 0.825(3) 0.300(2) 0.221(5) 1. 0 0.8(2)
*end for ICSD #1950
结构二:引用回帖: *data for ICSD #4132
Coll Code 4132
Rec Date 1980/01/01
Mod Date 2000/07/15
Chem Name Dilanthanum Dititanate
Structured La2 (Ti2 O7)
Sum La2 O7 Ti2
ANX A2B2X7
D(calc) 5.78
Title Zur Kristallstruktur von La2 Ti2 O7
Author(s) Scheunemann, K.;Mueller-Buschbaum, H.
Reference Journal of Inorganic and Nuclear Chemistry
(1975), 37, 1879-1881
Unit Cell 25.745 7.81 5.547 90. 90. 90.
Vol 1115.33
Z 8
Space Group P n a 21
SG Number 33
Cryst Sys orthorhombic
Pearson oP88
Wyckoff a22
R Value .07
Red Cell P 5.547 7.81 25.745 90 89.999 89.999 1115.327
Trans Red 0.000 0.000 -1.000 / 0.000 1.000 0.000 / 1.000 0.000 0.000
Comments At least one temperature factor is implausible or
meaningless but agrees with the value given in the paper.
Atom # OX SITE x y z SOF H ITF(B)
Ti 1 +4 4 a 0.0922 0.1364 0.7844 1. 0 0.32
Ti 2 +4 4 a 0.1943 0.1355 0.2507 1. 0 0.17
Ti 3 +4 4 a 0.312 0.115 0.7608 1. 0 0.53
Ti 4 +4 4 a 0.4169 0.1204 0.296 1. 0 0.64
La 1 +3 4 a 0.0557 0.3788 0.3024 1. 0 0.22
La 2 +3 4 a 0.2024 0.3721 0.7507 1. 0 0.41
La 3 +3 4 a 0.3088 0.3751 0.25 1. 0 0.58
La 4 +3 4 a 0.4589 0.3728 0.8383 1. 0 0.72
O 1 -2 4 a 0.035 0.134 0.577 1. 0 0.63
O 2 -2 4 a 0.048 0.121 0.041 1. 0 0.55
O 3 -2 4 a 0.099 0.378 0.806 1. 0 0.79
O 4 -2 4 a 0.14 0.145 0.455 1. 0 0.38
O 5 -2 4 a 0.154 0.119 0.957 1. 0 0.84
O 6 -2 4 a 0.207 0.366 0.186 1. 0 0.33
O 7 -2 4 a 0.248 0.135 0.504 1. 0 0.92
O 8 -2 4 a 0.258 0.103 0.009 1. 0 0.46
O 9 -2 4 a 0.301 0.379 0.767 1. 0 0.82
O 10 -2 4 a 0.355 0.148 0.459 1. 0 0.97
O 11 -2 4 a 0.368 0.09 0.974 1. 0 1.12
O 12 -2 4 a 0.402 0.373 0.186 1. 0 0.46
O 13 -2 4 a 0.458 0.133 0.558 1. 0 0.74
O 14 -2 4 a 0.473 0.112 0.073 1. 0 1.03
*end for ICSD #4132
结构三:
*data for ICSD #32537
Coll Code 32537
Rec Date 1982/12/31
Mod Date 2003/04/01
Chem Name Dilanthanum Dititanate - Ht
Structured La2 (Ti2 O7)
Sum La2 O7 Ti2
ANX A2B2X7
D(calc) 5.6
Title Compounds with perovskite-type slabs. V. A high-temperature
modification of La2 Ti2 O7
Author(s) Ishizawa, N.;Marumo, F.;Iwai, S.I.
Reference Acta Crystallographica B (24,1968-38,1982)
(1982), 38, 368-372
Phase Transition
(1992), 38, 127-220
Unit Cell 3.954(2) 25.952(8) 5.607(2) 90. 90. 90.
Vol 575.36
Z 4
Space Group C m c 21
SG Number 36
Cryst Sys orthorhombic
Pearson oS44
Wyckoff a11
R Value .066
Red Cell C 3.954 5.607 13.125 90 98.662 89.999 287.679
Trans Red -1.000 0.000 0.000 / 0.000 0.000 1.000 / 0.500 0.500 0.000
Comments Stable above 1770 K (2nd ref., Tomaszewski), below P21
Temperature in Kelvin: 1173
At least one temperature factor missing in the paper.
Atom # OX SITE x y z SOF H ITF(B)
La 1 +3 4 a 0 0.44609(6) 0.75 1. 0 0
La 2 +3 4 a 0 0.29808(8) 0.1757(5) 1. 0 0
Ti 1 +4 4 a 0.5 0.4404(1) 0.2452(11) 1. 0 0
Ti 2 +4 4 a 0.5 0.3370(1) 0.7095(8) 1. 0 0
O 1 -2 4 a 0.5 0.5088(9) 0.475(5) 1. 0 3.2
O 2 -2 4 a 0.5 0.4077(8) 0.542(4) 1. 0 2.3
O 3 -2 4 a 0.5 0.2964(8) 0.458(5) 1. 0 2.8
O 4 -2 4 a 0 0.4511(8) 0.255(7) 1. 0 2.9
O 5 -2 4 a 0 0.3472(7) 0.720(5) 1. 0 3.
O 6 -2 4 a 0.5 0.3891(10) 0.039(6) 1. 0 3.6
O 7 -2 4 a 0.5 0.2818(8) 0.935(4) 1. 0 2.2
*end for ICSD #32537
[/quote]
结构四(结构一的坐标变换):引用回帖: *data for ICSD #72433
Coll Code 72433
Rec Date 1994/01/19
Chem Name Lanthanum Dititanate
Structured La2 (Ti2 O7)
Sum La2 O7 Ti2
ANX A2B2X7
D(calc) 5.79
Title The twin structure of La2Ti2O7: X-ray and transmission electron
microscopy studies
Author(s) Schmalle, H.W.;Williams, T.;Reller, A.;Linden, A.;Bednorz, J.G.
Reference Acta Crystallographica B (39,1983-)
(1993), 49, 235-244
Unit Cell 7.812(2) 5.5440(7) 13.010(2) 90. 98.66(1) 90.
Vol 557.04
Z 4
Space Group P 1 21 1
SG Number 4
Cryst Sys monoclinic
Pearson mP44
Wyckoff a22
R Value .04
Red Cell P 5.544 7.812 13.01 98.66 90 90 557.036
Trans Red 0.000 -1.000 0.000 / -1.000 0.000 0.000 / 0.000 0.000 -1.000
Comments Temperature in Kelvin: 298
Structure determined on a twinned crystal
Atom # OX SITE x y z SOF H
La 1 +3 2 a 0.27895(3) 0.2565(1) 0.11366(2) 1. 0
La 2 +3 2 a 0.77399(3) 0.2610(1) 0.09946(2) 1. 0
La 3 +3 2 a 0.35036(3) 0.8092(1) 0.39101(2) 1. 0
La 4 +3 2 a 0.85240(3) 0.8477(1) 0.41598(2) 1. 0
Ti 1 +4 2 a 0.0315(1) 0.7661(2) 0.11873(5) 1. 0
Ti 2 +4 2 a 0.5273(1) 0.7648(2) 0.12005(5) 1. 0
Ti 3 +4 2 a 0.0787(1) 0.2973(2) 0.32308(5) 1. 0
Ti 4 +4 2 a 0.5834(1) 0.3008(2) 0.32632(5) 1. 0
O 1 -2 2 a 0.7763(4) 0.7983(6) 0.1058(3) 1. 0
O 2 -2 2 a 0.2737(4) 0.6985(6) 0.0934(2) 1. 0
O 3 -2 2 a 0.0302(4) 0.0247(5) 0.0159(2) 1. 0
O 4 -2 2 a 0.4776(4) 0.0256(5) 0.0180(3) 1. 0
O 5 -2 2 a 0.0991(4) 0.9683(6) 0.2263(3) 1. 0
O 6 -2 2 a 0.5141(4) 0.9604(6) 0.2295(3) 1. 0
O 7 -2 2 a 0.0309(5) 0.4588(6) 0.1866(2) 1. 0
O 8 -2 2 a 0.5612(4) 0.4546(5) 0.1860(2) 1. 0
O 9 -2 2 a 0.0875(5) 0.5593(6) 0.4087(3) 1. 0
O 10 -2 2 a 0.6161(5) 0.5706(6) 0.3991(3) 1. 0
O 11 -2 2 a 0.1208(4) 0.0778(5) 0.4313(2) 1. 0
O 12 -2 2 a 0.5992(5) 0.0846(5) 0.4394(2) 1. 0
O 13 -2 2 a 0.3277(4) 0.3247(6) 0.3098(2) 1. 0
O 14 -2 2 a 0.8255(4) 0.2210(6) 0.3042(3) 1. 0
Lbl Type U11 U22 U33 U12 U13 U23
La1 La3+ 0.00569(8) 0.00409(8) 0.00560(7) -.00017(6) 0.00201(6) -.00079(6)
La2 La3+ 0.00590(8) 0.00503(8) 0.00567(7) -.00022(6) 0.00194(6) -.00104(7)
La3 La3+ 0.00599(8) 0.0091(1) 0.0135(1) 0.00060(7) 0.00309(7) 0.00409(7)
La4 La3+ 0.00593(8) 0.00400(8) 0.00772(8) -.00012(6) 0.00174(6) 0.00089(6)
Ti1 Ti4+ 0.0064(2) 0.0031(2) 0.0040(2) -.0002(2) 0.0022(2) 0.0003(2)
Ti2 Ti4+ 0.0064(2) 0.0027(2) 0.0040(2) 0.0001(2) 0.0023(2) 0.0001(2)
Ti3 Ti4+ 0.0078(2) 0.0041(2) 0.0041(2) 0.0002(2) 0.0023(2) 0.0006(2)
Ti4 Ti4+ 0.0070(2) 0.0037(2) 0.0045(2) -.0005(2) 0.0014(2) 0.0006(2)
O1 O2- 0.005(1) 0.008(1) 0.014(1) 0.0009(9) 0.0023(9) 0.0025(9)
O2 O2- 0.006(1) 0.008(1) 0.006(1) -.0001(9) 0.0027(8) -.0002(8)
O3 O2- 0.011(1) 0.003(1) 0.007(1) 0.0005(8) 0.0019(9) -.0008(8)
O4 O2- 0.009(1) 0.004(1) 0.008(1) -.0002(8) 0.0009(9) -.0001(8)
O5 O2- 0.011(1) 0.006(1) 0.009(1) -.0004(9) 0.0013(9) -.0027(9)
O6 O2- 0.014(1) 0.006(1) 0.007(1) -.0004(9) 0.0008(9) -.0025(8)
O7 O2- 0.009(1) 0.007(1) 0.005(1) -.0015(9) -.0001(9) 0.0027(8)
O8 O2- 0.009(1) 0.004(1) 0.005(1) 0.0001(8) 0.0012(8) 0.0015(8)
O9 O2- 0.012(1) 0.005(1) 0.009(1) -.0013(9) 0.003(1) -.0007(8)
O10 O2- 0.009(1) 0.008(1) 0.018(2) -.002(1) 0.004(1) -.004(1)
O11 O2- 0.006(1) 0.005(1) 0.005(1) 0.0004(9) 0.0014(8) 0.0007(8)
O12 O2- 0.008(1) 0.004(1) 0.008(1) -.0009(9) 0.0029(9) -.0003(8)
O13 O2- 0.005(1) 0.014(1) 0.007(1) -.0001(9) 0.0002(8) 0.0001(9)
O14 O2- 0.007(1) 0.010(1) 0.010(1) 0.0007(9) 0.0039(9) 0.0020(9)
*end for ICSD #72433