Jump to content

User:Benjah-bmm27/degree/3/MFH

From Wikipedia, the free encyclopedia

Crystallography, MFH

[edit]

Texts

[edit]
  • Otterbein College: learn molecular symmetry with Jmol
  • Werner Massa, Crystal Structure Determination (2004)
  • Bill (William) Clegg, Crystal Structure Determination (Oxford Chemistry Primer) (1998)
  • Glusker, J. P.; Lewis, M.; Rossi, M. Crystal Structure Analysis for Chemists and Biologists.
  • International Tables for Crystallography Volume C. doi:10.1107/97809553602060000103.

Topics

[edit]

Unit cells, lattices and symmetry

[edit]

Crystal symmetry

[edit]
Crystal systems
[edit]
crystal system cell edge restriction cell angle restriction
triclinic none none
monoclinic none α = γ = 90°
orthorhombic none α = β = γ = 90°
tetragonal a = b α = β = γ = 90°
trigonal, hexagonal a = b α = β = 90°, γ = 120°
cubic a = b = c α = β = γ = 90°
Bravais lattices
[edit]
pearson symbol lattice name commonly called
aP triclinic ?
mP monoclinic primitive ?
mC monoclinic C-centred ?
oP orthorhombic primitive ?
oA orthorhombic A-centred ?
oI orthorhombic body centred ?
oF orthorhombic (all-)face centred ?
tP tetragonal primitive ?
tI tetragonal body centred ?
hP trigonal or hexagonal primitive ?
hR rhombohedral, hexagonal setting ?
cP cubic primitive simple cubic
cI cubic body-centred body-centred cubic
cF cubic (all-)face centred face-centred cubic
Miller indices
[edit]
Bragg's law
[edit]
Misc
[edit]

Systematic absences

[edit]
absence when this is odd indicates presence of this symmetry element
h00 h 21 screw axis parallel to the a-axis
0k0 k 21 screw axis parallel to the b-axis
00l l 21 screw axis parallel to the c-axis
h0l h a-glide perpendicular to the b-axis
h0l l c-glide perpendicular to the b-axis
h0l h+l n-glide perpendicular to the b-axis
hkl k+l A-centred
hkl h+l B-centred
hkl h+k C-centred
hkl h+k+l I-centred
hkl one or two but not all
three of h, k, and l
F-centred


Solving the Phase Problem, Refinement of the Solution and Interpretation of the Results

[edit]

A cautionary tale: the quest for cyclopentadienyl cation

[edit]
C10H15+
pentamethylcyclopentadienyl cation
C10H17+
pentamethylcyclopentenyl cation

See also

[edit]