Dimer method - convergence criteria
Posted: Tue Mar 04, 2008 4:24 pm
I am currently investigating Cu on TiN and am interested in determining the transition states associated with diffusion on the surface. I have identified the relevant stable adsorption sites, and after unsuccessful attempts of using the NEB method (it is likely that the transition states are not along linear paths connecting these sites), I am using the dimer method to attempt to find the transition states. The energy differences between various adsorption sites are quite small (<0.2 eV), and I anticipate that the PES is relatively flat. I have found that for some of my runs, they appear to converge prematurely - that is, the force is below the EDIFFG specified in the INCAR file (-5E-4) but the curvature is still positive. Shouldn't it continue running (since the curvature is still positive), or is the force convergence enough to end the run? A copy of the DIMCAR and a portion of the INCAR are appended below.
Thanks for your help!
~ Jeff
Thanks for your help!
~ Jeff
Code: Select all
Step Force Torque Energy Curvature Angle
1 0.00470 1.73165 -195.76264 0.40234 27.99709
1 0.00470 0.17559 -195.76264 -0.04678 14.12131
2 0.00166 1.36137 -195.82663 0.67222 20.73637
2 0.00166 0.92982 -195.82663 0.09024 15.69645
3 0.00009 --- -195.84147 --- ---
ICHAIN = 2
IOPT = 2
DdR = 0.005
DRotMax = 4
DFNMin = 0.01
DFNMax = 1.0