[ase-users] PreconLBFGS and broken symmetry

[Jens Jørgen Mortensen]

Hi!

I'm running some optimizations with the new PreconLBFGS optimizer and it 
seems to be very fast.  But only if I turn off use of symmetry in my DFT 
code.  When I use symmetry (the initial structure has inversion 
symmetry), GPAW crashes like shown below because PreconLBFGS gives the 
DFT code some new positions that no longer have inversion symmetry.  Is 
this a bug in PreconLBFGS?

opt = PreconLBFGS(system,
                   precon=Exp(A=3),
                   use_armijo=True,
                   trajectory='opt.traj',
                   logfile='opt.log')

Jens Jørgen

Traceback (most recent call last):
   File "opt.py", line 50, in <module>
     opt.run(fmax=0.02)
   File "/home/niflheim/jensj/ase/ase/optimize/precon/lbfgs.py", line 
353, in run
     return Optimizer.run(self, fmax, steps)
   File "/home/niflheim/jensj/ase/ase/optimize/optimize.py", line 179, 
in run
     self.step(f)
   File "/home/niflheim/jensj/ase/ase/optimize/precon/lbfgs.py", line 
220, in step
     self.precon.make_precon(self.atoms)
   File "/home/niflheim/jensj/ase/ase/optimize/precon/precon.py", line 
171, in make_precon
     self.estimate_mu(atoms)
   File "/home/niflheim/jensj/ase/ase/optimize/precon/precon.py", line 
494, in estimate_mu
     dE_p_plus_v = -atoms_v.get_forces().reshape(-1)
   File "/home/niflheim/jensj/ase/ase/atoms.py", line 728, in get_forces
     forces = self._calc.get_forces(self)
   File "/home/niflheim/jensj/ase/ase/calculators/calculator.py", line 
425, in get_forces
     return self.get_property('forces', atoms)
   File "/home/niflheim/jensj/ase/ase/calculators/calculator.py", line 
457, in get_property
     self.calculate(atoms, [name], system_changes)
   File "/home/niflheim/jensj/gpaw/gpaw/calculator.py", line 265, in 
calculate
     self.set_positions(atoms)
   File "/home/niflheim/jensj/gpaw/gpaw/calculator.py", line 443, in 
set_positions
     spos_ac = self.initialize_positions(atoms)
   File "/home/niflheim/jensj/gpaw/gpaw/calculator.py", line 435, in 
initialize_positions
     self.wfs.set_positions(spos_ac, atom_partition)
   File "/home/niflheim/jensj/gpaw/gpaw/wavefunctions/fdpw.py", line 47, 
in set_positions
     WaveFunctions.set_positions(self, spos_ac, atom_partition)
   File "/home/niflheim/jensj/gpaw/gpaw/wavefunctions/base.py", line 
204, in set_positions
     self.kd.symmetry.check(spos_ac)
   File "/home/niflheim/jensj/gpaw/gpaw/symmetry.py", line 248, in check
     raise RuntimeError('Broken symmetry!')
RuntimeError: Broken symmetry!