LBONE: Difference between revisions

Latest revision as of 15:51, 3 March 2025

LBONE = .TRUE. | .FALSE.
Default: LBONE = .FALSE.

Description: LBONE adds the small B-component to the chemical shift tensor.

LBONE restores the small B-component of the wave function inside the PAW spheres in the linear-response calculation of the NMR chemical shift tensor. The POTCARs used in VASP are scalar-relativistic and the AE-partial waves are solutions of the scalar-relativistic Kohn-Sham equation for the spherical atom. These have a large (A) and a small (B) component. The latter is not retained on the POTCAR, but approximately restored when LBONE=.TRUE. ^[1]. LBONE only affects the one-center valence contributions to the chemical shift. The contribution of the core electrons includes the B-component by default.

References

↑ G. A. de Wijs, R. Laskowski, P. Blaha, R. W. A. Havenith, G. Kresse, and M. Marsman, NMR shieldings from density functional perturbation theory: GIPAW versus all-electron calculations, J. Chem. Phys. 146, 064115 (2017).

[dewijs:laskowski:jcp:2017-1] G. A. de Wijs, R. Laskowski, P. Blaha, R. W. A. Havenith, G. Kresse, and M. Marsman, NMR shieldings from density functional perturbation theory: GIPAW versus all-electron calculations, J. Chem. Phys. 146, 064115 (2017).

[1]

@@ Line 1: / Line 1: @@
 {{TAGDEF|LBONE|.TRUE. {{!}} .FALSE. | .FALSE.}}
-Description: {{TAG|LBONE}} calculates the two-center contributions to the chemical shift tensor.
+Description: {{TAG|LBONE}} adds the small ''B''-component to the chemical shift tensor.
 ----
-{{TAG|LBONE}} switches on two-center contributions to the NMR chemical shift tensor.
+{{TAG|LBONE}} restores the small ''B''-component of the wave function inside
-These are contributions due to the augmentation
+the PAW spheres in the linear-response calculation of the NMR chemical shift
-currents in other PAW spheres than the sphere with the atom for which the shift tensor is calculated.
+tensor. The POTCARs used in VASP are scalar-relativistic and the
-Typically these contributions are safely neglected.
+AE-partial waves are solutions of the scalar-relativistic Kohn-Sham
-It makes sense to include them for accurate calculations with hard potentials (<tt>*_h</tt>)
+equation for the spherical atom. These have a large (''A'') and a small (''B'') component.
-on systems containing (non-hydrogen) atoms from the top rows of the periodic
+The latter is not retained on the POTCAR, but approximately restored when {{TAG|LBONE}}=.TRUE. {{Cite|dewijs:laskowski:jcp:2017}}.
-table (B, C, N, O, F), typically with short bonds, e.g. C<sub>2</sub>H<sub>2</sub>, where
+{{TAG|LBONE}} only affects the one-center valence contributions to the chemical shift. The contribution of the core electrons includes the ''B''-component by default.
-effects up to a few ppm are possible. For such systems using standard potentials
-typically introduces larger inaccuracies. The two-center contributions are calculated using
-a multipole expansion of the current density that is represented on the plane wave grid.<ref name="dewijs:jcp:17"/>
-== Related Tags and Sections ==
+== Related tags and articless ==
 {{TAG|LCHIMAG}}
 == References ==
-<references>
-<ref name="dewijs:jcp:17"> As in Sec. III.A.3 of [http://aip.scitation.org/doi/10.1063/1.4810799 F. Vasconcelos, G.A. de Wijs, R. W. A. Havenith, M. Marsman, G. Kresse, J. Chem. Phys. 139, 014109 (2013).]</ref>
-</references>
-----
-[[The_VASP_Manual|Contents]]
-[[Category:INCAR]][[Category:NMR]]
+[[Category:INCAR tag]][[Category:NMR]]