EFERMI NEDOS: Difference between revisions
(Created page with "{{DISPLAYTITLE:EFERMI_NEDOS}} {{TAGDEF|EFERMI_NEDOS|[integer]|21}} Description: Choose the number of points in the Gauss-Legendre integration grid used to evaluate the Fermi–Dirac distribution and determine the Fermi level. {{Available|6.5.0}} ---- During the self-consistent solution of the electronic structure, the Fermi level is obtained by integrating the electronic density of states weighted by the Fermi–Dirac occupation function. By performing a variable tr...") |
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Revision as of 10:55, 15 October 2025
EFERMI_NEDOS = [integer]
Default: EFERMI_NEDOS = 21
Description: Choose the number of points in the Gauss-Legendre integration grid used to evaluate the Fermi–Dirac distribution and determine the Fermi level.
| Mind: Available as of VASP 6.5.0 |
During the self-consistent solution of the electronic structure, the Fermi level is obtained by integrating the electronic density of states weighted by the Fermi–Dirac occupation function. By performing a variable transformation, this integral can be efficiently evaluated using Gauss–Legendre quadrature. The parameter EFERMI_NEDOS controls the number of quadrature points used in this integration.
Increasing the number of integration points generally improves the precision of the computed Fermi level, particularly at low temperatures or in systems with sharp features in the density of states near the Fermi energy. However, very high values may lead to unnecessary computational overhead without a significant change in the resulting Fermi level. A short convergence test is recommended to find an optimal balance between accuracy and cost.