18 
Optimized by g92 MP2/6-31G* 
 C       0.0000000000         0.0000000000         0.0000000000
 C       0.0000000000         0.0000000000         1.5295643333
 C       1.4262815710         0.0000000000        -0.5525710463
 H      -0.5248810821         0.8957290034        -0.3595764981
 H      -0.5563119191        -0.8650050006        -0.3810777272
 C       0.8067562233         1.1761900564         2.0821357410
 C       2.2331136370         1.1761349162         0.0000122835
 H      -1.0280007497         0.0305127652         1.9106419808
 H       0.4417754461        -0.9395027461         1.8891406277
 H       1.4102308192         0.0304870605        -1.6488158880
 H       1.9211374975        -0.9395187791        -0.2705381656
 C       2.2330352437         1.1762837694         1.5295527777
 H       0.8228182772         1.1457089813         3.1783805827
 H       0.3118863610         2.1157014852         1.8001028334
 H       3.2611427596         1.1456055198        -0.3809728967
 H       1.7914078361         2.1156848035        -0.3594986814
 H       2.7893495621         2.0413215494         1.9105380039
 H       2.7579945569         0.2805855046         1.8890639203
