Dear all. I have been trying to compute the band edge of 2D TMDCs and I have tested the option with and without "assume_isolated=2D". I noticed that this flag strongly affects the positions of the band edges. For example, the VBM/CBM of MoS2 change from -5.93/-4.20 eV with "assume_isolated=2D" to -4.96/-3.23 eV without "assume_isolated=2D"; all values were computed with respect to the vacuum level, which is 0 eV in the first case and 0.08 eV in the second case; I used a quite significant vacuum area in the calculatons (~90 Ang).
I read the paper "Density functional perturbation theory for gated two-dimensional heterostructures: Theoretical developments and application to flexural phonons in graphene" by Sohier, Calandra add Mauri (Physical Review B 96, 75448), and I understood that the new method would make differences if one wants to investigate charged 2D materials, e.g. with charged defect, or 2D materials in a perpendicular electric field, but not in the case of pure MoS2, no charge, no field. I do not understand why such a large difference in the case of pure 2D layers. I will appreciate if someone could comment on this. Thank you for your time. Best regards, Juliana Morbec -- Juliana Morbec, PhD Research Associate - Prof. Kratzer's group University of Duisburg-Essen, Germany https://jmmorbec.wordpress.com/
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