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   1 O       O       1       C                               ; CARBONYL OXYGEN (C=O)
   2 O       OM      1       C                               ; CARBOXYL OXYGEN (CO-)
   3 O       OA      2       C       H                       ; HYDROXYL OXYGEN (OH)
   4 O       OW      2       H       H                       ; WATER OXYGEN
   5 N       N       3       H       C       C               ; PEPTIDE NITROGEN (N OR NH)
   6 N       NT      3       H       H       C               ; TERMINAL NITROGEN (NH2)
   7 N       NL      4       C       H       H       H       ; TERMINAL NITROGEN (NH3)
   8 N       NR5     2       C       C                       ; AROMATIC N (5-RING,2 BONDS)
   9 N       NR5*    3       C       C       H               ; AROMATIC N (5-RING,3 BONDS)
  10 N       NP      3       C       C       FE              ; PORPHYRIN NITROGEN
  11 C       C       3       C       O       *               ; BARE CARBON (PEPTIDE,C=O,C-N)
  12 ; Note that order is importante here because of wildcards.
  13 C       C3      4       H       H       H       *       ; ALIPHATIC CH3 GROUP
  14 C       C2      4       H       H       C       *       ; ALIPHATIC CH2 GROUP
  15 C       C1      4       H       C       *       *       ; ALIPHATIC CH GROUP
  16 C       CB      3       C       C       C               ; BARE CARBON (5-,6-RING)
  17 H       H       1       N                               ; HYDROGEN BONDED TO NITROGEN
  18 H       HO      1       O                               ; HYDROXYL HYDROGEN
  19 H       HW      1       OW                              ; WATER HYDROGEN
  20 H       HS      1       S                               ; HYDROGEN BONDED TO SULFUR
  21 H       HC      1       C                               ; HYDROGEN BONDED TO CARBON