Assertion: ß cristobalite | /r/HasProperty | wyckoff
Facets:
Source sentences:
text: The cubic C9-type structure for ß-cristobalite (Wyckoff 1925) is improbable because of two stereochemically unfavorable features: a 180° Si-O-Si angle and an Si-O bond length of 1.54 Å, whereas the corresponding values in tetragonal a-cristobalite are ~146° and 1.609 Å respectively.
text: The cubic C9-type structure for ß-cristobalite (Wyckoff 1925) is improbable because of two stereochemically unfavorable features: a 180° Si-O-Si angle and an Si-O bond length of 1.54 Å, whereas the corresponding values in tetragonal a-cristobalite are ~146° and 1.609 Å respectively.