[OfficialAnu]

I used a software to generate resonance structures and they don't quite match.

E, the first and last resonance structure, matches with 4 on the software
A seems to match with 2, just different orientations
B matches with 1
C also matches with 1, also a different orientation of B, but I am not sure if it is truly a resonance structure
D matches with 2, also a different orientation of A. Again, I am not sure if it would be a resonance then.
The only one that I don't have that the software has is 3.

So I got a total of 5 resonance structures, two of which have different orientations (B & C, D & A). The computer software (MarvinSketch) got 4 total resonance structures, none of which have different orientations. And I am apparently missing one (#3) of the four structures generated by the software. Can anyone please explain?

[mjc123]

1 and 2 have symmetry-related forms, as you have drawn. 3 has 3 separate charges, and shouldn't really count for the reasons I've given in another post. (What's more, it has two negative charges adjacent! How unstable is that?)