hello,
Aside from setting LCALCPOL = .TRUE., which is important for ferroelectricity calculations, is the DIPOL tag also necessary in VASP? If so, how should its value be selected? My material is 2D.
Additionally, could you clarify the role of the IBRION tag in ferroelectricity calculations for 2D materials? What settings are recommended for accurate results?
Thank you for your help!
Hello,
VASP already has a decent default for DIPOL. For 2D materials, you can set DIPOL to the center of mass of all the atoms in the cell. Keep in mind that you still need to activate multi-pole corrections via IDIPOL for DIPOL to have any effect.
The IBRION tag controls how the crystal structure changes during the simulation. The different modes are explained on the VASP wiki. At the very bottom of the page you can find links to how-to pages that showcase and explain the various use cases, as this is too broad of a subject to cover here.