4

Si     -0.217703046161334      0.020310356140109      0.372891488662967
Si      1.520157522245720      1.379707772205792      0.231724703487815
Si      1.451990547358804      0.136160820792240      1.264292601603787
Si      0.129682178517933      1.719805276800390      1.674035137528129