misplaced lone pairs in 5.3.8

I'm having problems with the placement of lone pairs on the canvas in MarvinSketch 5.3.8.

When an electron flow arrow is drawn to make a structure octet-rule compliant, one of the lone pairs from the central atom is moved to an adjacent bond as is one of the lone pairs from the (leftmost in this case) ligand atom. That structure/presentation is completely at odds with the ordinary lay-out for Lewis structures.

The more standard and acceptable behavior can be seen in the 5.2.4 version of the same problem.

Right now I have 700 students puzzling over this problem. I'm sure there will be more.

I'm also wondering if it might have anything to do with the other discussion topic: "disappearing MEFlow object in MarvinSketch 5.3.8"

Any suggestions on how to address this?

Thanks,

   Michiel

Yes: back out to Marvin 5.2.6.  Peter Csizmadia was working on the electron-flow arrow package when he died unexpectedly, and ChemAxon is only now cleaning up the mess.

bobgr wrote:

Yes: back out to Marvin 5.2.6.  Peter Csizmadia was working on the electron-flow arrow package when he died unexpectedly, and ChemAxon is only now cleaning up the mess.

I wish it were that simple. The entire data tree under the applet has changed, which means that we had to rewrite our XML parser to take that into account.

I'll talk to our IS staff, but finding out how big the "mess" is is worthwhile too. (Just not at the expense of students on a timed semester schedule.)

Thanks,

   Michiel