What is the reference zero energy for the eigenvalues in VASP.

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TING QIN
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What is the reference zero energy for the eigenvalues in VASP.

#1 Post by TING QIN » Mon Mar 12, 2007 3:56 pm

Within the framework of pseudopotential, eignenvalues at different k points can be calculated. Their absolute values are not meaningful. However, what is the reference zero energy for them? Is the average potential within the unit cell or the potential at infinity taken as zero point of the potential?
Last edited by TING QIN on Mon Mar 12, 2007 3:56 pm, edited 1 time in total.

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What is the reference zero energy for the eigenvalues in VASP.

#2 Post by admin » Wed Mar 14, 2007 3:15 pm

there is no uniquely defined energy zero in 3D-systems with periodic boundary conditions. Please have a look to some solid state theory textbook.
for slab calculations with sufficiently large vacuum , the potential level of the vacuum can be taken as zero energy reference.
Please have a look into the handbook (LOCPOT-file, LVTOT input tag)
Last edited by admin on Wed Mar 14, 2007 3:15 pm, edited 1 time in total.

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