I am a beginner of rietveld refinement. I try to refine silicon standart
with FullProf 3.5, but I can not obtain good R values. How can I refine
till good R values. We have rigaku diffractometer.My starting pcr file is
following:
***************************************************************************
COMM si
! Files => DAT-file: 1, PCR-file: 1
!Job Npr Nph Nba Nex Nsc Nor Dum Iwg Ilo Ias Res Ste Nre Cry Uni Cor
0 7 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0
!
!Ipr Ppl Ioc Mat Pcr Ls1 Ls2 Ls3 Syo Prf Ins Rpa Sym Hkl Fou Sho Ana
0 1 1 0 1 0 0 0 1 0 0 0 0 0 0 0 0
!
! lambda1 Lambda2 Ratio Bkpos Wdt Cthm muR AsyLim Rpolarz
1.540562 1.540562 1.0000 25.0000 25.0000 0.7981 0.0000 30.00 0.0000
!
!NCY Eps R_at R_an R_pr R_gl Thmin Step Thmax PSD Sent0
11 0.03 1.00 1.00 1.00 1.00 20.0000 0.0100 90.0000 0.000 0.000
!
!
1 !Number of refined parameters
!
! Zero Code Sycos Code Sysin Code Lambda Code MORE
0.0000 00.00 0.0000 0.00 0.0000 0.00 0.000000 0.00 1
!
! Microabsorption coefficients
! P0 Cod_P0 Cp Cod_Cp Tau Cod_Tau
0.0000 0.00 0.0000 0.00 0.0000 0.00
! Background coefficients/codes
0.0000 0.0000 00.0000 0.0000 0.00000 0.00000
00.000 00.000 00.000 00.000 0.000 0.000
!-------------------------------------------------------------------------------
! Data for PHASE number: 1 ==> Current R_Bragg: 94.14
!-------------------------------------------------------------------------------
Si
!
!Nat Dis Mom Pr1 Pr2 Pr3 Jbt Irf Isy Str Furth ATZ Nvk Npr More
1 0 0 1.0 1.0 1.0 0 0 0 0 0 0.00 0 7 0
!
F d 3 m <--Space group symbol
!Atom Typ X Y Z Biso Occ In Fin N_t /Codes
Si SI 0.00000 0.00000 0.00000 0.60000 1.00000 0 0 0
0.00 0.00 0.00 0.00 0.00
! Scale Shape1 Bov Str1 Str2 Str3 Strain-Model
0.000000000 0.0000 0.0000 0.0000 0.0000 0.0000 0
11.00000 0.00 0.00 0.00 0.00 0.00
! U V W X Y GauSiz LorSiz Size-Model
00.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0
00.00 00.00 000.00 000.00 0.00 0.00 0.00
! a b c alpha beta gamma
5.43000000 5.430000 5.43000 90.000000 90.000000 90.000000
00.00000 00.00000 00.00000 0.00000 0.00000 0.00000
! Pref1 Pref2 Asy1 Asy2 Asy3 Asy4
0.00000 0.00000 0.00000 0.00000 0.00000 0.00000
0.00 0.00 00.00 0.00 0.00 0.00
**************************************************************************
Thanks in Advance
Selcuk Kevran
Ankara University
Physics Department