请教结构方面的问题

版主兄弟，怎么上传的威望值不是50了或系统有误？ 帮个忙把！！！

呵呵，系统出错了，有时候我上传东西都有问题
你说的这个化合物我用pcpdfwin找并没有找到，而是AgInS2，或者干脆AgInS8，也没有你说的正交对称性，奇怪。
不过看晶胞参数的确有点怪。没有XRD谱吗？对一下3.45 A的峰是什么面好了。

你看看这张图和你的衍射很像
就是高指数面的差了点，

a轴=7.001000,b轴=8.278000,c轴=6.698000

alpha=90.00,beta=90.00,gamma=90.00

电子束方向[2,1,-4]

(hkl)1 (hkl)2 倒易失量比 倒易失量夹角 强度比例
(-5,2,-2) (-1,2,0) 2.889241 45.196576 1.000000
(-4,0,-2) (-1,2,0) 2.296901 63.189946 1.000000
(-4,4,-1) (-1,2,0) 2.718621 22.149791 1.000000
(-3,-2,-2) (-1,2,0) 2.050315 88.994470 1.000000
(-3,2,-1) (-1,2,0) 1.831644 34.028585 1.000000
(-3,6,0) (-1,2,0) 3.000000 -0.000001 1.000000
(-2,-4,-2) (-1,2,0) 2.265354 115.185416 1.000000
(-2,0,-1) (-1,2,0) 1.148450 63.189946 1.000000
(-2,4,0) (-1,2,0) 2.000000 -0.000001 1.000000
(-1,-6,-2) (-1,2,0) 2.838991 133.772914 1.000000
(-1,-2,-1) (-1,2,0) 1.132677 115.185416 1.000000
(-1,2,0) (-1,2,0) 1.000000 0.000000 1.000000
(-1,6,1) (-1,2,0) 2.685330 -22.439240 1.000000
(0,-4,-1) (-1,2,0) 1.801937 145.331173 1.000000
(0,4,1) (-1,2,0) 1.801937 -34.668830 1.000000
(1,-6,-1) (-1,2,0) 2.685330 157.560763 1.000000
(1,-2,0) (-1,2,0) 1.000000 -180.000002 1.000000
(1,2,1) (-1,2,0) 1.132677 -64.814587 1.000000
(1,6,2) (-1,2,0) 2.838991 -46.227089 1.000000
(2,-4,0) (-1,2,0) 2.000000 -180.000002 1.000000
(2,0,1) (-1,2,0) 1.148450 -116.810057 1.000000
(2,4,2) (-1,2,0) 2.265354 -64.814587 1.000000
(3,-6,0) (-1,2,0) 3.000000 -180.000002 1.000000
(3,-2,1) (-1,2,0) 1.831644 -145.971418 1.000000
(3,2,2) (-1,2,0) 2.050315 -91.005533 1.000000
(4,-4,1) (-1,2,0) 2.718621 -157.850212 1.000000
(4,0,2) (-1,2,0) 2.296901 -116.810057 1.000000
(5,-2,2) (-1,2,0) 2.889241 -134.803427 1.000000



(hkl) Dhkl
(-10,-8,-7) 0.495901
(-10,-4,-6) 0.570158
(-10,0,-5) 0.620474
(-10,4,-4) 0.616584
(-10,8,-3) 0.561231
(-9,-10,-7) 0.487711
(-9,-6,-6) 0.579247
(-9,-2,-5) 0.663985
(-9,2,-4) 0.695451
(-9,6,-3) 0.648401
(-9,10,-2) 0.558924
(-8,-8,-6) 0.573337
(-8,-4,-5) 0.690643
(-8,0,-4) 0.775593
(-8,4,-3) 0.758131
(-8,8,-2) 0.655281
(-7,-10,-6) 0.553724
(-7,-6,-5) 0.692989
(-7,-2,-4) 0.840744
(-7,2,-3) 0.891332
(-7,6,-2) 0.787078
(-7,10,-1) 0.634832
(-6,-8,-5) 0.670297
(-6,-4,-4) 0.868871
(-6,0,-3) 1.034123
(-6,4,-2) 0.972601
(-6,8,-1) 0.769063
(-5,-10,-5) 0.629115
(-5,-6,-4) 0.847564
(-5,-2,-3) 1.140316
(-5,2,-2) 1.233168
(-5,6,-1) 0.972340
(-5,10,0) 0.712584
(-4,-8,-4) 0.786393
(-4,-4,-3) 1.146673
(-4,0,-2) 1.551185
(-4,4,-1) 1.310561
(-4,8,0) 0.890730
(-3,-10,-4) 0.707182
(-3,-6,-3) 1.048524
(-3,-2,-2) 1.737742
(-3,2,-1) 1.945203
(-3,6,0) 1.187640
(-3,10,1) 0.774932
(-2,-8,-3) 0.906778
(-2,-4,-2) 1.572787
(-2,0,-1) 3.102370
(-2,4,0) 1.781459
(-2,8,1) 0.981591
(-1,-10,-3) 0.771442
(-1,-6,-2) 1.254995
(-1,-2,-1) 3.145573
(-1,2,0) 3.562919
(-1,6,1) 1.326809
(-1,10,2) 0.798372
(0,-8,-2) 0.988636
(0,-4,-1) 1.977272
(0,4,1) 1.977272
(0,8,2) 0.988636
(1,-10,-2) 0.798372
(1,-6,-1) 1.326809
(1,-2,0) 3.562919
(1,2,1) 3.145573
(1,6,2) 1.254995
(1,10,3) 0.771442
(2,-8,-1) 0.981591
(2,-4,0) 1.781459
(2,0,1) 3.102370
(2,4,2) 1.572787
(2,8,3) 0.906778
(3,-10,-1) 0.774932
(3,-6,0) 1.187640
(3,-2,1) 1.945203
(3,2,2) 1.737742
(3,6,3) 1.048524
(3,10,4) 0.707182
(4,-8,0) 0.890730
(4,-4,1) 1.310561
(4,0,2) 1.551185
(4,4,3) 1.146673
(4,8,4) 0.786393
(5,-10,0) 0.712584
(5,-6,1) 0.972340
(5,-2,2) 1.233168
(5,2,3) 1.140316
(5,6,4) 0.847564
(5,10,5) 0.629115
(6,-8,1) 0.769063
(6,-4,2) 0.972601
(6,0,3) 1.034123
(6,4,4) 0.868871
(6,8,5) 0.670297
(7,-10,1) 0.634832
(7,-6,2) 0.787078
(7,-2,3) 0.891332
(7,2,4) 0.840744
(7,6,5) 0.692989
(7,10,6) 0.553724
(8,-8,2) 0.655281
(8,-4,3) 0.758131
(8,0,4) 0.775593
(8,4,5) 0.690643
(8,8,6) 0.573337
(9,-10,2) 0.558924
(9,-6,3) 0.648401
(9,-2,4) 0.695451
(9,2,5) 0.663985
(9,6,6) 0.579247
(9,10,7) 0.487711
(10,-8,3) 0.561231
(10,-4,4) 0.616584
(10,0,5) 0.620474
(10,4,6) 0.570158
(10,8,7) 0.495901

flashpoint果然是作图高手，不过低指数面在衍射上的数值相差这么大允许么？chmliubh自己量出来的HRTEM image上是多大的面间距？我怎么老觉得结构有点偏，不是正六角？

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斑竹兄，多谢指点！
我和那位仁兄核对了一下，化合物的确是AgInS2。不好意思，呵呵！
他给我的pdf数据如下，
AgInS2, orthorhombic,space group: Pna21(33)

2 theta d(Ang) hkl
24.992 3.56 120
25.427 3.50 200
26.586 3.350 002
28.382 3.142 121
28.756 3.102 201
36.805 2.440 122
37.120 2.420 202
43.692 2.07 040
44.530 2.033 320
48.049 1.892 123
48.266 1.884 203

3.45 A的衍射点不能很好的对应。考虑到相机常数的误差，它或许是200 或 002。 那么是否可以认为带轴方向是沿系列？？

但nbd和高分辨像所显示此晶体有三次对称轴（面夹角为60/120度），我不明白在orthorhombic 结构里是存在三次对称轴。因为不懂群理论，很迷惑！望多多指点？

[quote]原文由 flashpoint 发表:你看看这张图和你的衍射很像
就是高指数面的差了点，

a轴=7.001000,b轴=8.278000,c轴=6.698000

alpha=90.00,beta=90.00,gamma=90.00

电子束方向[2,1,-4]

(hkl)1 (hkl)2 倒易失量比 倒易失量夹角 强度比例
(-5,2,-2) (-1,2,0) 2.889241 45.196576 1.000000
(-4,0,-2) (-1,2,0) 2.296901 63.189946 1.000000
(-4,4,-1) (-1,2,0) 2.718621 22.149791 1.000000
(-3,-2,-2) (-1,2,0) 2.050315 88.994470 1.000000
(-3,2,-1) (-1,2,0) 1.831644 34.028585 1.000000
(-3,6,0) (-1,2,0) 3.000000 -0.000001 1.000000
(-2,-4,-2) (-1,2,0) 2.265354 115.185416 1.000000
(-2,0,-1) (-1,2,0) 1.148450 63.189946 1.000000
(-2,4,0) (-1,2,0) 2.000000 -0.000001 1.000000
(-1,-6,-2) (-1,2,0) 2.838991 133.772914 1.000000
(-1,-2,-1) (-1,2,0) 1.132677 115.185416 1.000000
(-1,2,0) (-1,2,0) 1.000000 0.000000 1.000000
(-1,6,1) (-1,2,0) 2.685330 -22.439240 1.000000
(0,-4,-1) (-1,2,0) 1.801937 145.331173 1.000000
(0,4,1) (-1,2,0) 1.801937 -34.668830 1.000000
(1,-6,-1) (-1,2,0) 2.685330 157.560763 1.000000
(1,-2,0) (-1,2,0) 1.000000 -180.000002 1.000000
(1,2,1) (-1,2,0) 1.132677 -64.814587 1.000000
(1,6,2) (-1,2,0) 2.838991 -46.227089 1.000000
(2,-4,0) (-1,2,0) 2.000000 -180.000002 1.000000
(2,0,1) (-1,2,0) 1.148450 -116.810057 1.000000
(2,4,2) (-1,2,0) 2.265354 -64.814587 1.000000
(3,-6,0) (-1,2,0) 3.000000 -180.000002 1.000000
(3,-2,1) (-1,2,0) 1.831644 -145.971418 1.000000
(3,2,2) (-1,2,0) 2.050315 -91.005533 1.000000
(4,-4,1) (-1,2,0) 2.718621 -157.850212 1.000000
(4,0,2) (-1,2,0) 2.296901 -116.810057 1.000000
(5,-2,2) (-1,2,0) 2.889241 -134.803427 1.000000
--------------------
非常感谢flashpoint兄的热心指点。
感叹兄弟在晶体学和衍射方面造诣。
从高分辨和NBD上看，此样品有三次对称轴。兄弟能否再帮忙指点一下，在orthorhomic 结构中有没有三次对称轴？

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我从HRTEM image上量出来的面间距和NBD 一致，三个方向面间距差不多，是2.01~2.04。