【求助】【请教】关于GSAS精修

另外精修完后每个峰的计算强度和实测强度总是差那么一点，这又是什么原因呢？现在迷茫中，恳求高手解释，谢谢大家了。

你好！
看了一下你的数据，你精修的挺好了！
问题:
1.你未对结构做精修（原子位置）；
2.你的温度因子未精修；
3.峰形函数参数还不是很正确；
谢谢参考！
精修数据只要小于15%都是可靠的。所以不要强求7%左右。
我初步做了一下，13% 10%.
祝你好运！
xujun16@163.com

非常感谢你的帮助，确实原子位置和温度因子没有修正。
峰型参数也是我自己给的一个初始值，不知道怎么能得到它的准确值呢？还是一直进行精修，一步步逼近？望赐教，再次感谢xujun16版友。祝你工作顺利。

没用过gsas，我用fullprof精修了一下，结果如下：



**********************************************************
** PROGRAM FullProf.2k (Version 4.70 - Oct2009-ILL JRC) **
**********************************************************
M U L T I -- P A T T E R N
Rietveld, Profile Matching & Integrated Intensity
Refinement of X-ray and/or Neutron Data


Date: 17/03/2002 Time: 20:48:55.405

=> PCR file code: 99860
=> DAT file code: LiFePO4.GSA -> Relative contribution: 1.0000
=> Title: A theoretical study of olivine Li M P O4 cathodes

==> CONDITIONS OF THIS RUN FOR PATTERN No.: 1

=> Global Refinement of X-ray powder diffraction data
=> Global Refinement of X-ray powder diffraction data
Bragg-Brentano or Debye-Scherrer geometry
=> The 5th default profile function was selected

=> Data read from GSAS file for pattern: 1
=> Wavelengths: 1.54056 1.54439
=> Cos(Monochromator angle)= 0.9100
=> Absorption correction (AC), muR-eff = 0.0000
=> Base of peaks: 2.0*HW* 8.00
==> Angular range, step and number of points:
2Thmin: 3.000000 2Thmax: 79.980003 Step: 0.020000 No. of points: 3850
=>-------> Pattern# 1
=> Crystal Structure Refinement for phase: 1
=> Scor: 2.1737

==> RESULTS OF REFINEMENT:


=> No. of fitted parameters: 43


------------------------------------------------------------------------------
=> Phase No. 1 A theoretical study of olivine Li M P O4P n m a
------------------------------------------------------------------------------

=> No. of reflections for pattern#: 1: 207/2


==> ATOM PARAMETERS:

Name x sx y sy z sz B sB occ. socc. Mult

Li1 0.00000( 0) 0.00000( 0) 0.00000( 0) 4.760(976) 0.789(926) 4
Fe1 0.28221( 17) 0.25000( 0) 0.97408( 54) 0.152( 80) 0.582(683) 4
P1 0.09518( 37) 0.25000( 0) 0.41961( 101) 0.185(241) 0.563(662) 4
O1 0.09695( 95) 0.25000( 0) 0.74094( 192) 0.550(435) 0.625(734) 4
O2 0.45610( 112) 0.25000( 0) 0.20738( 152) 1.427(416) 0.635(746) 4
O3 0.16510( 78) 0.04752( 119) 0.28576( 102) 0.698(311) 1.201(999) 8

==> PROFILE PARAMETERS FOR PATTERN# 1

=> Cell parameters :
10.32733 0.00027
6.00612 0.00016
4.69181 0.00014
90.00000 0.00000
90.00000 0.00000
90.00000 0.00000

=> overall scale factor : 0.002704455 0.006360418
=> Eta(p-v) or m(p-vii) : 0.00000 0.00000
=> Overall tem. factor : 0.00000 0.00000
=> Halfwidth parameters : 0.05102 0.00729
-0.06551 0.00639
0.03194 0.00125
=> Preferred orientation: 0.00000 0.00000
0.00000 0.00000
=> Asymmetry parameters : 0.00000 0.00000
0.00000 0.00000
0.00000 0.00000
0.00000 0.00000
=> X and y parameters : 0.01896 0.00000
0.00000 0.00000
=> Strain parameters : 0.00000 0.00000
0.00000 0.00000
0.00000 0.00000
=> Size parameters (G,L): 0.00000 0.00000
0.00000 0.00000

==> GLOBAL PARAMETERS FOR PATTERN# 1


=> Zero-point: 0.0263 0.0009
=> Background Polynomial Parameters ==>
465.799 355.034
-405.188 327.409
535.857 320.670
-240.291 373.523
-72.2440 305.506
-1234.09 557.664
1464.93 596.393
375.411 939.174
-623.213 633.106
-17596.0 15274.4
77093.2 44936.2
-82664.3 54199.5

=> Cos( theta)-shift parameter : 0.0000 0.0000
=> Sin(2theta)-shift parameter : 0.0000 0.0000

==> RELIABILITY FACTORS WITH ALL NON-EXCLUDED POINTS FOR PATTERN: 1

=> Cycle: 1 => MaxCycle: 50
=> N-P+C: 3807
=> R-factors (not corrected for background) for Pattern: 1
=> Rp: 10.2 Rwp: 15.0 Rexp: 4.13 Chi2: 13.2 L.S. refinement
=> Conventional Rietveld R-factors for Pattern: 1
=> Rp: 15.4 Rwp: 19.2 Rexp: 5.29 Chi2: 13.2
=> Deviance: 0.533E+05 Dev* : 14.00
=> DW-Stat.: 1.1970 DW-exp: 1.9225
=> N-sigma of the GoF: 531.291

==> RELIABILITY FACTORS FOR POINTS WITH BRAGG CONTRIBUTIONS FOR PATTERN: 1

=> N-P+C: 2971
=> R-factors (not corrected for background) for Pattern: 1
=> Rp: 10.8 Rwp: 15.9 Rexp: 4.13 Chi2: 14.8 L.S. refinement
=> Conventional Rietveld R-factors for Pattern: 1
=> Rp: 12.8 Rwp: 18.0 Rexp: 4.69 Chi2: 14.8
=> Deviance: 0.472E+05 Dev* : 15.87
=> DW-Stat.: 1.3648 DW-exp: 1.9157
=> N-sigma of the GoF: 532.255

=> Global user-weigthed Chi2 (Bragg contrib.): 16.9

-----------------------------------------------------
BRAGG R-Factors and weight fractions for Pattern # 1
-----------------------------------------------------

=> Phase: 1
=> Bragg R-factor: 2.70 Vol: 291.020( 0.014) Fract(%): 100.00(*****)
=> Rf-factor= 2.31 ATZ: 631.037 Brindley: 1.0000


CPU Time: 0.716 seconds
0.012 minutes

=> Run finished at: Date: 17/03/2002 Time: 20:48:56.138

精修的图：

十分感谢daxu版友，我用Rietan这个精修程序精修的结果跟您用fullprof精修的结果差不多。
个人感觉这个程序输出的拟合谱图比GSAS要好看，应该是IgorPro这个软件输出的吧？
Fullprof这个程序我没有用过，有机会学学，再次感谢daxu版友！

daxu(daxu) 发表:精修的图：