Singe Point Energy - Trebonius91/utils4VASP GitHub Wiki

If you only want to calculate the energy of a system with high precision, some minor changes of the default settings might be made. The number of k-points should be raised in comparison to the geometry optimization or the molecular dynamics trajectory (if a screenshot of it has been taken), e.g., 4x4x1 instead of 2x2x1. The final energy can be found in the OUTCAR file:

   FREE ENERGIE OF THE ION-ELECTRON SYSTEM (eV)
  ---------------------------------------------------
  free  energy   TOTEN  =      -956.59244435 eV

  energy  without entropy=     -956.33674483  energy(sigma->0) =     -956.50721118

The reported energy should always be the one with sigma (the smearing width or electronic temperature) extrapolated to zero (energy(sigma->0)), in this case: -956.50721118 eV.

List of possible keyword changes in the INCAR file:

• ISMEAR = -5 Activates the Tetrahedron Smearing with Blöchl corrections, the best one, if only energies are needed (or ISMEAR = 0 (Gaussian) with a very small SIGMA (e.g., 0.01).
• PREC = Accurate The overall precision (of the FFT) might be raised.
• IBRION = -1 No positional updates
• NSW = 0 The structure is calculated only once.