[QE-users] NEB images with different cell parameters possible?

[A. Jain]

Hi All,

I would like to conduct an neb study on my system (ruthenium based 
crystals) where photoisomerisation takes place. We would like to 
investigate the mechanism of photoisomerisation. However the ground 
state and irradiated states (geometries obtained via accurate xrd 
experiments) have very slightly different cell parameters due to the 
magnitude of the photoisomerisation.

The Ground State values are :Axis (Ang): A=8.3891, B=12.5019, C=13.1614. 
Angles (deg): a=99.481, b=98.613, c=90.27.
Excited state: Axis (Ang): A=8.4845, B=12.4241, C=13.3243. Angles (deg): 
a=101.456, b=98.732, c=91.001.
As you can see the values effectively only change by 1%.

So I would like to know if is it possible to conduct neb on images whose 
cell parameters also change, ie I would use the ground state as the 
starting image and the excited state as the final image? I expect the 
answer is no. If not, has anybody come across a similar problem or has 
any suggestions for how I could approach this issue?

Thank you for your help.

Apoorv Jain (PhD Student)
Department of Physics, University of Cambridge