# ctrm : assignment criterium R=ring; N=normal   
# type : gaff type
# hybr/conn: hybridization  
# 
#
# crtm   type   hybr/conn    gaff03 description
1  R     c      sp2          carbon in C=O, C=S
2  N     c1     sp1          carbon                                     
3  N     c2     sp2          carbon, aliphatic
4  R     c3     sp3          carbon                                     
5  R     ca     sp2          carbon, aromatic
6  N     n      sp2          nitrogen in amides                         
7  N     n1     sp1          nitrogen
8  N     n2     sp2          nitrogen with 2 subst., real double bonds  
9  N     n3     sp3          nitrogen with 3 subst.
10 N     n4     sp3          nitrogen with 4 subst.                     
11 R     na     sp2          nitrogen with 3 subst.
12 N     nh     sp3          amine  nitrogen                                  
13 N     no     sp2          Nitrogen in nitro groups             
14 N     o      sp2          sp2 oxygen in C=O, COO-                
15 N     oh     sp3          oxygen in hydroxyl groups            
16 RN    os     sp3          oxygen in ethers and esters            
17 N     s2     sp2          sulfur (p=S, C=S, etc.)              
18 N     sh     sp3          sulfur in thiol groups         
19 RN    ss     sp3          sulfur in —SR and S—S                
20 N     s4     sp3+         hypervalent sulfur, 3 subst.           
21 RN    s6     sp3+         hypervalent sulfur, 4 subst.                 
22 N     p2     sp2          phosphorus (C=P, etc.)         
23 N     p3     sp3          phosphorus, 3 subst.                 
24 N     p4     sp3+         hypervalent phosphorus, 3 subst.    
25 RN    p5     sp3+         hypervalent phosphorus, 4 subst.     
26 N     hc      -           hydrogen on aliphatic carbon           
27 N     ha      -           hydrogen on aromatic carbon                  
28 N     hn      -           hydrogen on nitrogen                   
29 N     ho      -           hydrogen on oxygen                   
30 N     hs      -           hydrogen on sulfur             
31 N     hp      -           hydrogen on phosphorus                       
32 N     f       -           any fluorine                           
33 N     cl      -           any chlorine                                 
34 N     br      -           any bromine                         
35 N     i       -           any iodine                           
36 R     cc(cd) sp2          inner sp2 carbon in conjugated ring systems
37 N     ce(cf) sp2          inner carbon in conjugated chain systems
38 N     cp(cq) sp2          bridge aromatic carbon in biphenyl systems
39 R     cu     sp2          carbon in three-membered rings
40 R     cv     sp2          carbon in four-membered rings        
41 R     cx     sp3          carbon in three-membered rings   
42 R     cy     sp3          carbon in four-membered rings        
43 R     nb     sp3          aromatic nitrogen
44 R     nc(nd) sp2          inner nitrogen in conjugated ring systems, 2 subst.
45 N     ne(nf) sp2          inner nitrogen in conjugated chain systems, 2 subst.
46 R     pb     sp3          aromatic phosphorus
47       pc(pd) sp2          inner phosphorus in conjugated chain systems, 2 subst.
48       pe(pf) sp2          inner phosphorus in conjugated ring systems, 2 subst.
49       px     sp2+         conjugated phosphorus, 3 subst.                            
50       py     sp3+         conjugated phosphorus, 4 subst. 
51       sx     sp2+         conjugated sulfur, 3 subst.                               
52       sy     sp3+         conjugated sulfur, 4 subst.
53 N     h1     -            hydrogen on aliphatic carbon with 1 electron-withdrawal group     
54 N     h2     -            hydrogen on aliphatic carbon with 2 electron-withdrawal groups
55 N     h3     -            hydrogen on aliphatic carbon with 3 electron-withdrawal groups
56 N     h4     -            hydrogen on aromatic carbon with 1 electron-withdrawal group connected to aromatic rings
57       h5     -            hydrogen on aromatic carbon with 2 electron-withdrawal groups
