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LMAXFOCKAE

LMAXFOCKAE= [integer] (maximum L quantum number for accurate charge augmentation in Hartree-Fock routines)

Default for GW type calculations: LMAXFOCKAE= 4

For accurate QP eigenvalues of systems with localized electrons, the flag LMAXFOCKAE must be set. Usually VASP restores only the moments of the all electron charge density on the plane wave grid up to a certain radial quantum number $ l$. If LMAXFOCKAE is set, the shape of the charge density is restored accurately on the plane wave grid up to a typical plane wave energy of 100 eV. Beyond that cutoff the polarizability is usually very small ($ < 0.01$), necessitating no accurate treatment.

Restoring the charge density on the plane wave grid with high precision allows to obtain accurate QP energies, even though the one-center-terms are not implemented in VASP for the GW case. The flag must be selected for GW calculations involving transition metals (LMAXFOCKAE=4) and/or first row elements (LMAXFOCKAE=2). See also Secs. 6.71.6 and 6.71.7. In the present code version the default for LMAXFOCKAE is 4, sufficient for most materials.

Even higher precision may be obtained by additionally setting NMAXFOCKAE= 2 (the default is NMAXFOCKAE= 1). This allows to restore the AE-charge density up to a typical plane wave energy of 400 eV. In most cases, differences between NMAXFOCKAE= 1 and NMAXFOCKAE= 2 are, however, very small.


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Next: NOMEGA, NOMEGAR number of Up: Frequency dependent GW calculations Previous: ALGO for response functions   Contents   Index
N.B. Requests for support are to be addressed to: vasp.materialphysik@univie.ac.at