QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: jrussell on May 30, 2012, 20:10

Title: Geometry optimization, lattice vectors
Post by: jrussell on May 30, 2012, 20:10

Dear ATK,

I am a little confused about how to perform a geometry optimization where both
cartesian coordinates and lattice vectors are optimized.

Is this method still valid:
http://quantumwise.com/forum/index.php?topic=29.msg77#msg77 (http://quantumwise.com/forum/index.php?topic=29.msg77#msg77)

Or is optimization of lattice vectors implied when you use disable_stress=false
 in the OptimizeGeometry part of the input file?

Code

bulk_configuration = OptimizeGeometry(
        bulk_configuration,
        max_forces=0.05*eV/Ang,
        max_stress=5.0e-3*Units.eV/Units.Ang**3
        max_steps=2000,
        max_step_length=0.5*Ang,
        trajectory_filename='wire3-5traj.nc',
        disable_stress=False,
        optimizer_method=QuasiNewton(),
        )

I really appreciate the help!
Sincerely,
John

Title: Re: Geometry optimization, lattice vectors
Post by: Anders Blom on May 30, 2012, 22:46

No, the link you refer to is outdated. It was for an older version of ATK that did not implement the computation of the stress.

So for the current ATK, you are correct that the lattice vectors will be optimized if disable_stress is False.