4 Si 0.149777555970285 0.093644321539677 0.273541036547340 O 1.532739635050214 1.522409891693018 -0.104007624175541 O 1.561779843582407 -0.011851384255832 1.311132695001135 Si 0.291192563847456 1.306912291017673 1.661889860222413