Hi,
I am interested in calculating the bulk energy of an oxide (ABO3-type) with a O2- vacancy. To do that, I removed one oxygen atom from the supercell (cubic), and further reduced the total electrons by 2 to make the system +2 charged. I find that the total energy is less (by almost 16eV) than the system with neutral vacancy --all the parameters were kept same.
Obviously, this cannot be correct -- what is going wrong? Do I need to add the dipole correction for the charged system separately. If yes, what flags, needs to be set for the bulk (manual says that IDIPOL=1-3 is for slab and 4 for atoms/molecules)?
Regards
MC
Energy of a charged bulk system
Moderators: Global Moderator, Moderator
-
Mahesh_chandran
- Newbie
- Posts: 8
- Joined: Wed Jun 15, 2005 11:27 am
- Location: Bangalore, INDIA.
Energy of a charged bulk system
Last edited by Mahesh_chandran on Thu Mar 16, 2006 11:07 am, edited 1 time in total.
-
admin
- Administrator
- Posts: 2921
- Joined: Tue Aug 03, 2004 8:18 am
- License Nr.: 458
Energy of a charged bulk system
1) please choose the size of the unit cell as large as possible (defect concentration!)
2) yes, for the charged system multipole corrections should be applied : LDIPOL=True,DIPOL=(center of the dipol). Please have a look at
http://cms.mpi.univie.ac.at/vasp/vasp/node137.html
for a more detailled explanation
2) yes, for the charged system multipole corrections should be applied : LDIPOL=True,DIPOL=(center of the dipol). Please have a look at
http://cms.mpi.univie.ac.at/vasp/vasp/node137.html
for a more detailled explanation
Last edited by admin on Mon Mar 20, 2006 2:33 pm, edited 1 time in total.