Hi Giane B. Damas

Few years back I was able to perform spin-polarized calculations to get the forces using finite displacement method (phonopy). My system was Metal-Organic periodic chains in gas phase. What is the error message when you try to get the forces? In my understanding partitioning of spin in case of complex systems is not straight forward. In particular systems on surface give you wrong spins. You may want to apply constraint on occupation.

Hi Naseem Ud Din ,

Thank you for your reply.

I get an error on parsing the vasprun.xml file on the first folder, which is common to get when the calculation has not ended successfully. But after repeating the same calculation a couple of times and not verifying any intrinsic error with it, I guessed it would be something with the magnetization.

End of slurm file on folder 1:

"1 F= -.10770963E+04 E0= -.10770229E+04 d E =-.146858E+00 mag= 0.9766

mpprun info: Elapsed time (h:m:s): 0:34:13.020811 "

Details on OUTCAR file (last column is the occupation in the orbital)

"Spin component 1

K-point 1 0 0 0

....

705 1.2594 1.00000

706 1.2869 0.99998

707 1.3125 0.99991

708 1.3774 0.99774

709 1.4026 0.99348

710 1.4527 0.96202

711 1.4957 0.87833

712 1.5364 0.72257

713 1.5899 0.43426

....

"

How do you apply such constraint on occupation as you mentioned? I have been using Gaussian smearing because I am working within the gamma point for the electronic calculations. I also thought to perform these single points removing the magnetization, but I am not sure how reliable that would be.

Thank you in advance.

You can try this example for constraint local magnetic moment. "https://www.vasp.at/wiki/index.php/Constraining_the_local_magnetic_moments"

You can see that the occupation for spin polarized went wrong. You can have 1 or 0 occupation for spin polarized and 2 or 0 for non spin polarized case.

"1 F= -.10770963E+04 E0= -.10770229E+04 d E =-.146858E+00 mag= 0.9766

Is this line showing force components along x, y and z direction? If so then the structure after displacement went crazy. Starting from relaxed structure if we displace atoms with displacement amplitude ~0.01 or ~0.005 we don't expect such huge force.

Turning off magnetization will give you wrong vibrational frequencies.

Hi Naseem Ud Din ,

Thank you for your explanation. I will try it out.

This line is actually the end of the first (and only) ionic step from OSZICAR, with total energy as the first value and other energy values afterwards.

Thank you again