[ase-users] error with ag

[Janne Blomqvist]

pgmoses wrote:
> ag used to work like at charm, but I updated it today and now I get the
> following error when trying to read a trajectory file
[snip]
> AttributeError: class FixAtoms has no attribute '__new__'

Er,

this seems to be my fault. Sorry about that. As part of making 
constraints work properly with Atoms.__getitem__(), I made them inherit 
from object (new-style classes). This was around r643-r649 (no link 
since ase-svncheckings wasn't up and running then). Then in r750 jensj 
made them old-style classes again, presumably he hit the same problem as 
you:

https://listserv.fysik.dtu.dk/pipermail/ase-svncheckins/2009-January/000096.html

I suppose you could temporarily add back the object superclass to 
FixConstraint, read in your trajectory, write it out in some other 
format, make FixConstraint old-style once again, read in the trajectory 
and write it out in .traj format.

-- 
Janne Blomqvist