atom list starts with C
  Mrv2007 05282011072D          

  0  0  0     0  0            999 V3000
M  V30 BEGIN CTAB
M  V30 COUNTS 5 5 0 0 0
M  V30 BEGIN ATOM
M  V30 1 [C,N,O] -4.9583 2.185 0 0
M  V30 2 C -6.2042 1.2798 0 0
M  V30 3 C -5.7283 -0.1848 0 0
M  V30 4 C -4.1883 -0.1848 0 0
M  V30 5 C -3.7125 1.2798 0 0
M  V30 END ATOM
M  V30 BEGIN BOND
M  V30 1 1 1 2
M  V30 2 1 3 4
M  V30 3 1 1 5
M  V30 4 2 2 3
M  V30 5 2 4 5
M  V30 END BOND
M  V30 END CTAB
M  END
$$$$
atom list starts with N
  Mrv2007 05282011072D          

  0  0  0     0  0            999 V3000
M  V30 BEGIN CTAB
M  V30 COUNTS 5 5 0 0 0
M  V30 BEGIN ATOM
M  V30 1 [N,C,O] -4.9583 2.185 0 0
M  V30 2 C -6.2042 1.2798 0 0
M  V30 3 C -5.7283 -0.1848 0 0
M  V30 4 C -4.1883 -0.1848 0 0
M  V30 5 C -3.7125 1.2798 0 0
M  V30 END ATOM
M  V30 BEGIN BOND
M  V30 1 1 1 2
M  V30 2 1 3 4
M  V30 3 1 1 5
M  V30 4 2 2 3
M  V30 5 2 4 5
M  V30 END BOND
M  V30 END CTAB
M  END
$$$$
single member atom list
  Mrv2007 05282011072D          

  0  0  0     0  0            999 V3000
M  V30 BEGIN CTAB
M  V30 COUNTS 5 5 0 0 0
M  V30 BEGIN ATOM
M  V30 1 [C] -4.9583 2.185 0 0
M  V30 2 C -6.2042 1.2798 0 0
M  V30 3 C -5.7283 -0.1848 0 0
M  V30 4 C -4.1883 -0.1848 0 0
M  V30 5 C -3.7125 1.2798 0 0
M  V30 END ATOM
M  V30 BEGIN BOND
M  V30 1 1 1 2
M  V30 2 1 3 4
M  V30 3 1 1 5
M  V30 4 2 2 3
M  V30 5 2 4 5
M  V30 END BOND
M  V30 END CTAB
M  END
$$$$