IDIPOL and LDIPOL for slab
Posted: Sun May 17, 2009 9:41 pm
Dear All,
I am investigating a system which is a monolayer of one kind of atom on top of a slab of metal. I hope to soon be looking at very large supercells (300+ atoms) for DOS but before I can do that I need to make sure I understand the correct usage of LDIPOL and IDIPOL. In order to minimize the size of my system I would like to use an asymmetric slab (AABBBBBB). Which one of the following is the best use of these flags for my system?
1) LDIPOL = T and IDIPOL = 3 (z-direction)
2) or LDIPOL = F and IDIPOL = 3
3) or LDIPOL = T and ignore IDIPOL
4) none of these should be used
ONE MORE related important question: if I am studying a slab system that is symmetric (AABBBBBBBAA) instead of the asymmetric system I described above, do I still need to use LDIPOL or IDIPOL or none for the symmetric system?
I have done a lot of reading on the VASP forum and also the manual but it is not clear to me what the primary difference is between these two flags and when to use them.
Can someone please give me a brief summary of their meaning and the appropriate time to use them both for the symmetric and asymmetric cases?
My system is neutral (not charged) and has no defects.
Thank you very much in advance for your help. I look forward to hearing from you.
<span class='smallblacktext'>[ Edited ]</span>
I am investigating a system which is a monolayer of one kind of atom on top of a slab of metal. I hope to soon be looking at very large supercells (300+ atoms) for DOS but before I can do that I need to make sure I understand the correct usage of LDIPOL and IDIPOL. In order to minimize the size of my system I would like to use an asymmetric slab (AABBBBBB). Which one of the following is the best use of these flags for my system?
1) LDIPOL = T and IDIPOL = 3 (z-direction)
2) or LDIPOL = F and IDIPOL = 3
3) or LDIPOL = T and ignore IDIPOL
4) none of these should be used
ONE MORE related important question: if I am studying a slab system that is symmetric (AABBBBBBBAA) instead of the asymmetric system I described above, do I still need to use LDIPOL or IDIPOL or none for the symmetric system?
I have done a lot of reading on the VASP forum and also the manual but it is not clear to me what the primary difference is between these two flags and when to use them.
Can someone please give me a brief summary of their meaning and the appropriate time to use them both for the symmetric and asymmetric cases?
My system is neutral (not charged) and has no defects.
Thank you very much in advance for your help. I look forward to hearing from you.
<span class='smallblacktext'>[ Edited ]</span>