quasicrystals - 2024 ACF Regionals @ Imperial

Question

The oldest synthetic examples of these structures have been found in red trinitite, a mineral that formed from the Trinity test. For 10 points each:

[10h] Name these structures whose discovery in an aluminum–manganese alloy won Dan Schechtman a Nobel in Chemistry. These structures can fill space but lack translational symmetry, since they are ordered but aperiodic.

ANSWER: quasicrystals [or quasiperiodic crystals]

[10m] In 2009, the first naturally-occurring quasicrystal, which is named for having this symmetry, was discovered in a Russian meteorite. This crystallographically forbidden symmetry is exhibited by buckminsterfullerene.

ANSWER: icosahedral symmetry [or icosahedrite; or the symmetry of an icosahedron; or I-sub-h]

[10e] In 2022, Bindi et al. discovered another naturally-occurring quasicrystal that forms when this phenomenon interacts with eolian dunes. Fulgurite forms when these electrostatic discharges fuse sand into a glass.

ANSWER: lightning strikes

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Summary


2024 ACF Regionals @ Cornell	01/27/2024	Y	3	10.00	67%	0%	33%
2024 ACF Regionals @ JMU	01/27/2024	Y	9	11.11	100%	11%	0%
2024 ACF Regionals @ Minnesota	01/27/2024	Y	2	20.00	100%	50%	50%
2024 ACF Regionals @ Nebraska	01/27/2024	Y	6	13.33	100%	0%	33%
2024 ACF Regionals @ Ohio State	01/27/2024	Y	3	13.33	100%	0%	33%
2024 ACF Regionals @ Rutgers	01/27/2024	Y	5	10.00	80%	0%	20%
2024 ACF Regionals @ Imperial	01/27/2024	Y	8	13.75	100%	13%	25%
2024 ACF Regionals @ Vanderbilt	01/27/2024	Y	5	14.00	100%	0%	40%

Data


Durham B	Bristol	0	0	10	10
Durham A	Cambridge A	0	0	10	10
Edinburgh	Cambridge B	0	0	10	10
Warwick	Imperial A	10	0	10	20
Cambridge C	Imperial B	0	0	10	10
Kiel	KCL	0	10	10	20
Oxford A	Oxford B	10	0	10	20
Sheffield	Oxford C	0	0	10	10