Database of Zeolite Structures
 
Framework Type MEI
Powder Diffraction Pattern for ZSM-18, SiO2 Framework
Input Parameters
  Wavelength:  or
  2θ range:
  Step size:
  Polarization factor:
  Background:
  Reference peak is
    peak closest to °2θ
    reflection (hkl)
       scaled to
  Intensity axis:
     
Peak shape
  Pseudo-Voigt: (1-n)Gaussian + n Lorentzian
  FWHM = sqrt (U + V tan θ + W tan2θ)
  Mixing parameter (n): %
  Peak range: FWHM
  Peak width:
       set UVW at: U =   V =   W =
       Calculate UVW such that FWHM =
    FWHM =
       FWHM =
   
Select Output
 
List hkl and intensity
List powder pattern
plot powder pattern
Crystal Data
  Space group: P 63/m   (# 176)   
  Cell parameters: a = 13.175 Å b = 13.175Å c = 15.848 Å
    α = 90° β = 90° γ = 120 °
  Refinement: DLS refinement
  Reference: Lawton, S.L. and Rohrbaugh, W.J.
Science, 247, 1319-1321 (1990)
  Atomic Coordinates:          
   
Atom
Form Factor
x
y
z
PP
B(iso)
   
  SI1
Si
0.6667 0.3333 0.3495 1 0
  SI2
Si
0.6713 0.15 0.47 1 0
  SI3
Si
0.4522 0.1161 0.5682 1 0
  SI4
Si
0.5266 0.2118 0.75 1 0
  O1
O
0.6667 0.3333 0.25 1 0
  O2
O
0.6623 0.2169 0.3878 1 0
  O3
O
0.5793 0.1388 0.5411 1 0
  O4
O
0.4217 0.1984 0.5101 1 0
  O5
O
0.454 0.1495 0.6663 1 0
  O6
O
0.6506 0.2126 0.75 1 0
  O7
O
0.6443 0.02 0.4453 1 0