The charset

As I proposed in maxhodak/keras-molecules#54. I am interested in why the charset is designed like this. It's not straightforward. From the viewpoint of chemistry, the chlorine "Cl" should not be treated as "C" and "l". Maybe it will be some improvement if we re-design the charset. I used the implementation from keras-molecules, and when I tried to interpolate between 2 chemical structures (CC=C(C(=CC)c1ccc(O)cc1)c1ccc(O)cc1 and CN1C(=O)CCS(=O)(=O)C1c1ccc(Cl)cc1).
). I got something like these invalid structures below, so I guess the charset is the reason for this.
CC(C)(O)CCC1CCC(**Cr**)So2c1ccc(C)cc1
CCNC(=O)CN(CC**1**(**(l)**CN**1**c1ccc(OC)cc1
CN**1**C(=O)CN(CC**1**(**(#)**CN**1**c1ccc(OC)cc1
CN**1**C(=O)CC(CC**()**(=O)C**1**c1ccc(Cl)cc1
CN**1**C(=O)CC(NC**()**(=O)C**1**c1ccc(Cl)cc1