Limits of construction kit analogy - Revision history

Apm: Category:Surprising facts

2026-03-29T20:00:30Z

← Older revision		Revision as of 22:00, 29 March 2026
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	----		----
	* [http://ruby.colorado.edu/~smyth/min/zincite.html Info about zincite ZnO]		* [http://ruby.colorado.edu/~smyth/min/zincite.html Info about zincite ZnO]

			[[Category:Surprising facts]]

Apm: /* Related */ added link to yet unwritten page LEGO and its (un)suitability for nanoscale construction kits

2025-08-25T06:56:30Z

Related: added link to yet unwritten page LEGO and its (un)suitability for nanoscale construction kits

← Older revision		Revision as of 08:56, 25 August 2025
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	* [[Isostructural bending]]		* [[Isostructural bending]]
	* singlet triplet issues		* singlet triplet issues
			----
			* [[LEGO and its (un)suitability for nanoscale construction kits]]

	== External links ==		== External links ==

Apm: /* Look out for unusual coordination numbers */ fixed bromellite and made it a link

2024-02-16T09:57:22Z

Look out for unusual coordination numbers: fixed bromellite and made it a link

← Older revision		Revision as of 11:57, 16 February 2024
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	* stishovite SiO<sub>2</sub> (Mohs 9.5)		* stishovite SiO<sub>2</sub> (Mohs 9.5)
	* zincite ZnO (Mohs 4), ~~Brommelite~~ BeO (Mohs 9)		* zincite ZnO (Mohs 4), [[Bromellite]] BeO (Mohs 9)

	=== Look out for bounded instabilities ===		=== Look out for bounded instabilities ===

Apm: added image

2021-07-01T13:44:20Z

added image

← Older revision		Revision as of 15:44, 1 July 2021
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	~~{{stub}}~~		[[File:Knex-connexions-base.jpg ‎\|193px\|thumb\|right\|Construction kit analogy: A defined number of connection points in defined directions.]]

	In general atoms do not behave like building blocks of a construction toy.		In general atoms do not behave like building blocks of a construction toy.

Apm: /* Look out for bounded instabilities */ spelling: wurzite ~> wurtzite

2020-05-14T07:31:19Z

Look out for bounded instabilities: spelling: wurzite ~> wurtzite

← Older revision		Revision as of 09:31, 14 May 2020
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	Examples are:		Examples are:
	* Ions too small for their interstitial position may have two stable positions with a very small energy barrier in-between.		* Ions too small for their interstitial position may have two stable positions with a very small energy barrier in-between.
	* Rotational or vibrational degrees of freedom can become activated. <br> E.g. cristiobalite (a polymorph of SiO<sub>2</sub> with ~~wurzite~~ like structure akin to the hexagonal diamond form called lonsdaleite) has its α-β transition from low-temp-tetragonal to high-temp-cubic. The oxygen atoms that connect the silicon atoms indirectly are not straight but kinked connections (due to oxygens remaining lone pair of electrons). When they oxygen connections start to rotate at about 110°C the effect of the kinks start to get canceled out. Normal quartz has a similar α-β transition albeit at much higher temperature (at 573°C from trigonal to hexagonal).		* Rotational or vibrational degrees of freedom can become activated. <br> E.g. cristiobalite (a polymorph of SiO<sub>2</sub> with wurtzite like structure akin to the hexagonal diamond form called lonsdaleite) has its α-β transition from low-temp-tetragonal to high-temp-cubic. The oxygen atoms that connect the silicon atoms indirectly are not straight but kinked connections (due to oxygens remaining lone pair of electrons). When they oxygen connections start to rotate at about 110°C the effect of the kinks start to get canceled out. Normal quartz has a similar α-β transition albeit at much higher temperature (at 573°C from trigonal to hexagonal).
	* A lifting of quantum mechanical degeneracy by breaking symmetry lowers energy can occur. (Jahn–Teller effect)		* A lifting of quantum mechanical degeneracy by breaking symmetry lowers energy can occur. (Jahn–Teller effect)
	* More exotic compounds can even have sub-lattices melt.<br>E.g. iodides (AgI, CuI, ...) - the cation metal sub-lattice melts - see fast ion conductors		* More exotic compounds can even have sub-lattices melt.<br>E.g. iodides (AgI, CuI, ...) - the cation metal sub-lattice melts - see fast ion conductors

Apm: /* Related */ added link to page: Every structure permissible by physical law

2018-07-17T16:22:38Z

Related: added link to page: Every structure permissible by physical law

← Older revision		Revision as of 18:22, 17 July 2018
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	== Related ==		== Related ==

			* [[Every structure permissible by physical law]]
	* [[Surface passivation]]		* [[Surface passivation]]
	* [[Periodic table of elements]]		* [[Periodic table of elements]]

Apm: capitalisation

2017-08-16T02:06:41Z

capitalisation

← Older revision		Revision as of 04:06, 16 August 2017
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	Those leave no real freedom for the directions of bonds. The crystal structures (one of a very few very simple ones) is given by the radii of the combined elements.		Those leave no real freedom for the directions of bonds. The crystal structures (one of a very few very simple ones) is given by the radii of the combined elements.

	In case one needs a material only for structural elements (no [[~~kaehler~~ bracket\|fine tuned geometries]] and sliding interfaces) salts can be of use.		In case one needs a material only for structural elements (no [[Kaehler bracket\|fine tuned geometries]] and sliding interfaces) salts can be of use.

	Due to their polarity salts are often water soluble so its better to use them only in internal sealed spaces not exposed to weather attacked surfaces.		Due to their polarity salts are often water soluble so its better to use them only in internal sealed spaces not exposed to weather attacked surfaces.

Apm: /* Look out for bounded instabilities */ added note about quartz's α-β transition

2017-07-13T20:37:24Z

Look out for bounded instabilities: added note about quartz's α-β transition

← Older revision		Revision as of 22:37, 13 July 2017
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	Examples are:		Examples are:
	* Ions too small for their interstitial position may have two stable positions with a very small energy barrier in-between.		* Ions too small for their interstitial position may have two stable positions with a very small energy barrier in-between.
	* Rotational or vibrational degrees of freedom can become activated. <br> E.g. cristiobalite (a polymorph of SiO<sub>2</sub> with wurzite like structure akin to the hexagonal diamond form called lonsdaleite) has its α-β transition from low-temp-tetragonal to high-temp-cubic. The oxygen atoms that connect the silicon atoms indirectly are not straight but kinked connections (due to oxygens remaining lone pair of electrons). When they oxygen connections start to rotate at about 110°C the effect of the kinks start to get canceled out.		* Rotational or vibrational degrees of freedom can become activated. <br> E.g. cristiobalite (a polymorph of SiO<sub>2</sub> with wurzite like structure akin to the hexagonal diamond form called lonsdaleite) has its α-β transition from low-temp-tetragonal to high-temp-cubic. The oxygen atoms that connect the silicon atoms indirectly are not straight but kinked connections (due to oxygens remaining lone pair of electrons). When they oxygen connections start to rotate at about 110°C the effect of the kinks start to get canceled out. Normal quartz has a similar α-β transition albeit at much higher temperature (at 573°C from trigonal to hexagonal).
	* A lifting of quantum mechanical degeneracy by breaking symmetry lowers energy can occur. (Jahn–Teller effect)		* A lifting of quantum mechanical degeneracy by breaking symmetry lowers energy can occur. (Jahn–Teller effect)
	* More exotic compounds can even have sub-lattices melt.<br>E.g. iodides (AgI, CuI, ...) - the cation metal sub-lattice melts - see fast ion conductors		* More exotic compounds can even have sub-lattices melt.<br>E.g. iodides (AgI, CuI, ...) - the cation metal sub-lattice melts - see fast ion conductors

	While in most cases likely to avoid in construction materials for specific applications (temperature sensors?) these effects should be pretty useful.		While in most cases likely to avoid in construction materials for specific applications (temperature sensors?) these effects should be pretty useful.
			Note that for [[crystolecules]] there is no risk of fracturing due to sudden local inhomogeneous volume change since they are too small and usually faultless.

	== Related ==		== Related ==

Apm: /* Look out for bounded instabilities */ proper sentences for bulletpoints

2017-07-13T16:23:00Z

Look out for bounded instabilities: proper sentences for bulletpoints

← Older revision		Revision as of 18:23, 13 July 2017
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	Examples are:		Examples are:
	* Ions too small for their interstitial position ~~having~~ two stable positions with a very small energy barrier in-between.		* Ions too small for their interstitial position may have two stable positions with a very small energy barrier in-between.
	* Rotational or vibrational degrees of freedom become activated <br> E.g. cristiobalite (a polymorph of SiO<sub>2</sub> with wurzite like structure akin to the hexagonal diamond form called lonsdaleite) has its α-β transition from low-temp-tetragonal to high-temp-cubic. The oxygen atoms that connect the silicon atoms indirectly are not straight but kinked connections (due to oxygens remaining lone pair of electrons). When they oxygen connections start to rotate at about 110°C the effect of the kinks start to get canceled out.		* Rotational or vibrational degrees of freedom can become activated. <br> E.g. cristiobalite (a polymorph of SiO<sub>2</sub> with wurzite like structure akin to the hexagonal diamond form called lonsdaleite) has its α-β transition from low-temp-tetragonal to high-temp-cubic. The oxygen atoms that connect the silicon atoms indirectly are not straight but kinked connections (due to oxygens remaining lone pair of electrons). When they oxygen connections start to rotate at about 110°C the effect of the kinks start to get canceled out.
	* lifting of quantum mechanical degeneracy by breaking symmetry lowers energy (Jahn–Teller effect)		* A lifting of quantum mechanical degeneracy by breaking symmetry lowers energy can occur. (Jahn–Teller effect)
	* ~~more~~ exotic compounds can even have sub-lattices melt<br>E.g. iodides (AgI, CuI, ...) - the cation metal sub-lattice melts - see fast ion conductors		* More exotic compounds can even have sub-lattices melt.<br>E.g. iodides (AgI, CuI, ...) - the cation metal sub-lattice melts - see fast ion conductors

	While in most cases likely to avoid in construction materials for specific applications (temperature sensors?) these effects should be pretty useful.		While in most cases likely to avoid in construction materials for specific applications (temperature sensors?) these effects should be pretty useful.

Apm: /* Rules to get construction toy like behavior */ added subsection === Look out for bounded instabilities ===

2017-07-13T16:20:24Z

Rules to get construction toy like behavior: added subsection === Look out for bounded instabilities ===

@@ Line 72: / Line 72: @@
 * stishovite SiO<sub>2</sub> (Mohs 9.5)
-* zincite ZnO (Mohs 4), Brommelite BeO (Mohs 9),
+* zincite ZnO (Mohs 4), Brommelite BeO (Mohs 9)
 == Related ==