24小时热门版块排行榜    

查看: 1159  |  回复: 6

lyl163com

金虫 (正式写手)


[交流] 【请教】结构解析时都有哪些判断原子是否定错的方法

结构解析时都有哪些判断原子是否定错的方法
回复此楼

» 猜你喜欢

» 本主题相关价值贴推荐,对您同样有帮助:

» 抢金币啦!回帖就可以得到:

查看全部散金贴

已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
lyl163com(金币+5): 2011-03-31 17:10:44
主要是看温度因子
2楼2011-03-31 12:44:35
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

lyl163com

金虫 (正式写手)


引用回帖:
Originally posted by cluster8676 at 2011-03-31 12:44:35:
主要是看温度因子

那看温度因子,有没有判断的依据呢!或者是不是有表可查!比如O原子的温度因子一般是多少之类的!
3楼2011-03-31 13:32:05
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
lyl163com(金币+2): 2011-03-31 17:10:57
U值,键长键角是否合理,
4楼2011-03-31 14:57:11
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

xujun16

银虫 (著名写手)


lyl163com(金币+3): 2011-03-31 19:45:12
结构解析时都有哪些判断原子是否定错的方法?
Re: in general, isotropic displacement parameters, eg. B factor or U factor. (Uiso=Biso/78.96). (anisotropic atomic displacement parameters also work.)
  
    For inorganic ionic crystals and intermetallic compounds the typical range of B's is ~0.5 to ~1.0A; for other inorganic and many coordination compounds B varies from ~1 to ~3A, while for organic and organometallic compounds and for solvent or other intercalated non-bonded molecules or atoms this range extends from ~3 to ~10A or higher. If you isotropic displacement parameters in this range are reasonable.

        Hence, if the B becomes unphysical during the LS refinement, this usually means that the improper type of an atom has been placed in the suspicious site. There are two possibilities:

       (1) if the chemical element placed in a certain pisition has fewer electrons than is should, then during the refinement its diaplacement parameters becomes negative or much lower than those of the correctly placed atoms;

       (2) When the site has too many electrons than it really does, displacement parameters of the corresponding atom will be unusually high during the refinement.

Maybe helpful!
Reference: Fundamentals of Powder diffraction and Structural Characterization of Materials Vitalij K. Pecharsky 2003
5楼2011-03-31 19:20:49
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
★ ★
小木虫(金币+0.5):给个红包,谢谢回帖交流
yanhualover(金币+1): 谢谢交流 2011-04-01 13:05:35
我不知道书上是怎么写的,我师兄教我结晶体的时候告诉我,温度因子在0.05左右比较正常。如果温度因子超过0.15,或者很小比如0.0002, 就说明原子可能定错了
6楼2011-03-31 21:00:27
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

小木虫(金币+0.5):给个红包,谢谢回帖交流
但是如果原子序数太接近了,就需要其他的手段来证明了,比如质谱
7楼2011-04-02 01:13:43
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
相关版块跳转 我要订阅楼主 lyl163com 的主题更新
普通表情 高级回复 (可上传附件)
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[考研] 材料270求调剂 6+4 Eiiiio 2026-03-01 7/350 2026-03-02 20:17 by hypershenger
[考研] 0856求调剂285 +11 吕仔龙 2026-02-28 11/550 2026-03-02 20:15 by hypershenger
[考研] 材料复试调剂 +5 学材料的点 2026-03-01 6/300 2026-03-02 20:01 by hypershenger
[考研] 调剂 +3 13853210211 2026-03-02 3/150 2026-03-02 19:59 by hypershenger
[考研] 0854总分272 +3 打小就是老实人 2026-03-02 4/200 2026-03-02 19:49 by 求调剂zz
[考博] 26超级电容器申博 +3 dhdjdjend 2026-02-25 3/150 2026-03-02 19:21 by 轻松不少随
[考研] 268求调剂 +3 好运连绵不绝 2026-03-02 3/150 2026-03-02 19:05 by zhukairuo
[考研] 材料调剂 +3 恒顺自然 2026-03-02 3/150 2026-03-02 18:49 by L135790
[考研] 284求调剂 +5 天下熯 2026-03-02 5/250 2026-03-02 18:38 by caszguilin
[考研] 接收调剂 +6 津萌津萌 2026-03-02 13/650 2026-03-02 18:34 by fengyuling00
[考研] 一志愿东北大学材料专硕328,求调剂 +3 shs1083 2026-03-02 3/150 2026-03-02 17:27 by houyaoxu
[考研] 江苏省农科院招调剂1名 +4 Qwertyuop 2026-03-01 4/200 2026-03-02 14:27 by 升格阿达
[考研] 284求调剂 +10 天下熯 2026-02-28 11/550 2026-03-02 11:03 by 无际的草原
[考研] 一志愿郑大材料学硕298分,求调剂 +6 wsl111 2026-03-01 6/300 2026-03-02 11:00 by ydudjddnd
[考研] 材料调剂 +6 爱擦汗的可乐冰 2026-02-28 7/350 2026-03-02 10:42 by Jy?
[考研] 调剂 +3 13853210211 2026-03-02 4/200 2026-03-02 10:16 by 13853210211
[考研] 0854复试调剂 276 +4 wmm9 2026-03-01 6/300 2026-03-02 09:28 by 热情沙漠
[考研] 328求调剂 +3 aaadim 2026-03-01 5/250 2026-03-01 17:29 by njzyff
[考研] 0856材料求调剂 +4 麻辣鱿鱼 2026-02-28 4/200 2026-03-01 16:51 by caszguilin
[考研] 295复试调剂 +3 简木ChuFront 2026-03-01 3/150 2026-03-01 14:27 by zzxw520th
信息提示
请填处理意见