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2.3 Basic structure types
Pauling rules: understanding polyhedral structures
(
(3) The presence of shared edges, and particularly shared faces3) The presence of shared edges, and particularly shared faces
dec
decreases the stability of a structure. This is particularly trureases the stability of a structure. This is particularly truee
for cations with large valences and small CN.
for cations with large valences and small CN.
(4) In a crystal containing different4) In a crystal containing different cationscations those with largethose with large
(
v
valence and small CN do not tend to share polyhedronalence and small CN do not tend to share polyhedron
elements with each other.ements with each other.
el
(5) The number of chemically different coordination environments
(5) The number of chemically different coordination environments
for a given ion in a crystal tends to be small.
for a given ion in a crystal tends to be small.
