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Colored symmetry. (see Colored Symmetry by Shubnikov & Belov. Applications in: crystal surfaces & crystal growth strained materials twinning magnetic structures ferroelectrics other physical props textures. Colored symmetry. (see Colored Symmetry by Shubnikov & Belov.
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Colored symmetry (see Colored Symmetry by Shubnikov & Belov Applications in: crystal surfaces & crystal growth strained materials twinning magnetic structures ferroelectrics other physical props textures
Colored symmetry (see Colored Symmetry by Shubnikov & Belov Applications in: crystal surfaces & crystal growth strained materials twinning magnetic structures ferroelectrics other physical props textures Spin moment structure in MnO determined by neutron diffrn - only Mn+2 ions shown
Colored symmetry (see Colored Symmetry by Shubnikov & Belov Applications in: crystal surfaces & crystal growth strained materials twinning magnetic structures ferroelectrics other physical props textures Will consider here only two colors - black & white
Colored symmetry Anti-equality – Pair of gloves which are, say, black on outside & white on inside if both left-handed, can get: congruent equality - do nothing mirror anti-equality - turn one inside-out
Colored symmetry Anti-equality – Pair of gloves which are, say, black on outside & white on inside if both left-handed, can get: congruent equality - do nothing mirror anti-equality - turn one inside-out if right- & left-handed, can get: mirror equality - nothing congruent anti-equality - turn one inside-out
Colored symmetry New operations – anti-rotations (rotation + "sign change") 1' 2' 3' 4' 6' mirror anti-rotations (mirror rotation + "sign change") 1' 2' 3' 4' 6'
Colored symmetry New operations – anti-rotations (rotation + "sign change") 1' 2' 3' 4' 6' mirror anti-rotations (mirror rotation + "sign change") 1' 2' 3' 4' 6' c11 c12 c13 0 c21 c22 c23 0 c31 c32 c33 0 0 0 0 ±1
Colored symmetry Polar & neutral figures – polar white outside, black inside black outside, white inside neutral black inside & outside or white inside & outside
Colored symmetry Operations – mirror in xy plane - anti-symmetric 2' anti-reflection 1 0 0 0 0 1 0 0 0 0 -1 0 0 0 0 -1
Colored symmetry Operations – anti-rotation of 180° along x-axis 2' 1 0 0 0 0 -1 0 0 0 0 -1 0 0 0 0 -1
Colored symmetry Operations – anti-inversion 1' -1 0 0 0 0 -1 0 0 0 0 -1 0 0 0 0 -1
Colored symmetry Operations – 4'
Colored symmetry Operations – 4' 6' black underneath
Colored symmetry Operations – 2/m' black underneath
Colored symmetry Operations – 2/m' 2'/m white underneath black underneath
Colored symmetry Operations – 2'/m' black underneath white underneath
Colored symmetry Operations – 2'/m' 2'm'm black underneath white underneath
Colored symmetry Operations – 2m'm'
Colored symmetry Operations – 2m'm' 2'2'2
Colored symmetry Operations – 2/mm'm' black underneath white underneath
Colored symmetry Glides – g g' m=a' a=m'
Comments Mirror translation ( ) – gives another mirror of same character if uncolored. If colored, new mirror is colored Mirror translation (||) – colored translation gives colored glide
Comments Mirror translation ( ) – gives another mirror of same character if uncolored. If colored, new mirror is colored Mirror translation (||) – colored translation gives colored glide Axis translation ( ) – new axis has same charater if uncolored. If colored, new axis is colored or uncolored, depending on the axis. Character is unchanged by colored translation Axis translation (||) – colored translation makes axis colored screw or uncolored, depending on the axis
Comments 4. Axis translation (||) – colored translation makes axis colored screw or uncolored, depending on the axis 2 t||' ––> 2 & 21' 21 t||' ––> 21 & 2'
Comments 4. Axis translation (||) – colored translation makes axis colored screw or uncolored, depending on the axis 2 t||' ––> 2 & 21' 21 t||' ––> 21 & 2' 4 t||' ––> 4 & 42' 41 t||' ––> 41 & 43'
Comments n = odd axes cannot be black-white Two intersecting 2-fold axes: 30° ––> new 6 45° ––> new 4 60° ––> new 3 etc. new axis uncolored if 2-folds are same color…….otherwise, new axis is colored uncolored 4 colored 4