4

 C   -0.073549748998    1.954769120300    0.000000000000
 C   -0.024218557905    0.646152651097    0.000000000000
 C    0.024122437507   -0.646196524670    0.000000000000
 C    0.073645869396   -1.954725246727    0.000000000000