Interpretating a z-matrix

Determine the structure encoded in the following z-matrix, a MOPAC input file.
The first three atoms are dummy atoms, geometrical points without a chemical meaning. The file is generated by MODEL, which starts any z-matrix with three dummy atoms, to avoid accidental colinearity of the first three real atoms.
AM1 CHARGE=0
test z-matrx
bepaal structuur
  XX    0.000000  0    0.000000  0    0.000000  0   0  0  0  
  XX    3.062561  1    0.000000  0    0.000000  0   1  0  0  
  XX    3.399903  1   83.589203  1    0.000000  0   2  1  0  
   C    3.148290  1  108.087257  1   87.708336  1   3  2  1   
   C    1.337057  1  143.273621  1  295.313782  1   4  3  2   
   C    1.514669  1   99.483688  1   72.104385  1   4  3  2   
   H    1.100001  1   38.818802  1  221.108246  1   4  3  2  
   C    1.510262  1  107.360863  1  134.749222  1   5  4  3   
   H    1.100000  1  121.588982  1  314.749176  1   5  4  3   
   C    1.549365  1   99.106056  1   35.240181  1   8  5  4    
   C    1.548015  1  107.352333  1  290.625092  1   8  5  4   
   H    1.100000  1  113.595085  1  164.221405  1   8  5  4   
   H    1.110108  1  114.890648  1  188.178146  1  10  8  5   
   H    1.110107  1  114.890717  1   66.186409  1  10  8  5  
   C    1.543783  1  106.229164  1  276.552887  1   6  4  3    
   O    1.412155  1  112.804398  1   45.198032  1   6  4  3   
   H    1.110107  1  112.356056  1   52.039394  1  15  6  4   
   H    1.110108  1  112.356049  1  170.185242  1  15  6  4   
   C    1.520871  1  115.144569  1  299.698181  1  11  8  5   
   H    1.100000  1  112.338417  1  187.681351  1  11  8  5   
   O    1.210355  1  121.709763  1  348.813385  1  19 11  8    
   C    1.517915  1  117.535904  1  172.019867  1  19 11  8   
   H    1.109931  1  109.998970  1  180.000000  1  22 19 11   
   H    1.109879  1  109.999962  1  300.001801  1  22 19 11   
   H    1.109877  1  109.999992  1   59.998180  1  22 19 11   
   C    1.415230  1  114.481133  1  162.135223  1  16  6  4   
   H    1.109930  1  109.998993  1  180.000000  1  26 16  6   
   H    1.109878  1  109.999939  1  300.001740  1  26 16  6   
   H    1.109878  1  109.999969  1   59.998180  1  26 16  6
   0    0.0    
Draw a connectivity diagram, starting with 4, the first real atom.
Use the bond length information to detect double bonds.
After completion of the diagram open valencies should be combined, to close ring sub-structures. Two possibilities remain to do this. Use the bond and torsion angle information to distinguish between the two.

Structure (.moo file), to be read in by a visualizing tool.
See separate note on chemical MIME types.


Back to text of paragraph 1C.