question: What is the notion when the crystal structure is tetragonal and the formula is bi 2 sr 2 cacu 2 o 8
answer: SELECT notation FROM table_101336_1 WHERE crystal_structure = "Tetragonal" AND formula = "Bi 2 Sr 2 CaCu 2 O 8"
context: CREATE TABLE table_101336_1 (notation VARCHAR, crystal_structure VARCHAR, formula VARCHAR)