Silicon
Kasper J S, Richards S M
Acta Crystallographica 17 (1964) 752-755
The crystal structures of new forms of silicon and germanium
Locality: synthetic
_database_code_amcsd 0009282
6.636 6.636 6.636 90 90 90 Ia3
atom     x     y     z Biso
Si   .1003 .1003 .1003  .89