LNMR SYM RED: Difference between revisions

Revision as of 14:05, 6 April 2022

LNMR_SYM_RED = .TRUE. | .FALSE.
Default: LNMR_SYM_RED = .FALSE.

Description: discard symmetry operations that are not consistent with the way k-space derivatives are calculated in the linear-response calculations of chemical shifts.

The star on which the k-space derivative is calculated is oriented along the cartesian directions in k space. If the symmetry operations in k space do not map this star onto itself, erroneous results can be obtained. To check for such operations, set LNMR_SYM_RED=.TRUE.. VASP then disregards such operations and the resulting first Brillouin zone (IBZ) is larger. In case of any doubt set LNMR_SYM_RED=.TRUE.

Warning: It matters how the real-space-lattice vectors are set up relative to the cartesian coordinates in the POSCAR file.

It determines the orientation of the k-space star and, hence, can affect the efficiency via the number of k-points in the IBZ.

@@ Line 1: / Line 1: @@
 {{TAGDEF|LNMR_SYM_RED| .TRUE. {{!}} .FALSE. | .FALSE.}}
-Description: discard symmetry operations that are not consistent with the way ''k''-space derivative are calculated in the linear response calculations of chemical shifts.
+Description: discard symmetry operations that are not consistent with the way ''k''-space derivatives are calculated in the linear-response calculations of chemical shifts.
 ----
-The star on which the ''k''-space derivative is calculated is oriented along the cartesian directions in ''k''-space. If the symmetry operations in ''k''-space do not map this star onto itself, erroneous results can be obtained. To have VASP check for such operations, set {{TAG|LNMR_SYM_RED}}=.TRUE., and such operations will be discarded, resulting in a larger IBZ. In case of any doubt set {{TAG|LNMR_SYM_RED}}=.TRUE. Beware: It matters how the real space lattice vectors are set up relative to the cartesian coordinates in {{FILE|POSCAR}}. It determines the orientation of the ''k''-space star and hence can affect the efficiency via the number of ''k''-points in the IBZ.
+The star on which the ''k''-space derivative is calculated is oriented along the cartesian directions in ''k'' space. If the symmetry operations in ''k'' space do not map this star onto itself, erroneous results can be obtained. To check for such operations, set {{TAG|LNMR_SYM_RED}}=.TRUE.. VASP then disregards such operations and the resulting first Brillouin zone (IBZ) is larger. In case of any doubt set {{TAG|LNMR_SYM_RED}}=.TRUE.
+{{NB|warning|It matters how the real-space-lattice vectors are set up relative to the cartesian coordinates in the {{FILE|POSCAR}} file.}} It determines the orientation of the ''k''-space star and, hence, can affect the efficiency via the number of ''k''-points in the IBZ.
-== Related Tags and Sections ==
+== Related tags and articles ==
 {{TAG|LCHIMAG}},
 {{TAG|DQ}},
@@ Line 16: / Line 17: @@
 [[The_VASP_Manual|Contents]]
-[[Category:INCAR]][[Category:Electronic Minimization]][[Category:Electronic Minimization Methods]]
+[[Category:INCAR]][[Category:Electronic minimization]]