e+
e−
2D to 3D
C
H
N
O
P
S
F
Cl
Br
I
...
| Formula | |
| Molecular weight | |
| Hydrogen bond donors | |
| Hydrogen bond acceptors |
| Formula | |
| Molecular weight | |
| Hydrogen bond donors | |
| Hydrogen bond acceptors |
Despite these legal hurdles, many preservationists argue that their work falls under the "fair use" doctrine. Fair use allows for limited use of copyrighted material for purposes such as criticism, news reporting, teaching, and scholarship.