LBONE: Difference between revisions

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{{TAGDEF|LBONE|.TRUE. {{!}} .FALSE. | .FALSE.}}
{{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.
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{{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.<ref name="dewijs:jcp:17"/>
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}}
{{TAG|LCHIMAG}}


== References ==
== References ==
<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>
<ref name="dewijs:jcp:17">[http://aip.scitation.org/doi/10.1063/1.4975122 G. A. de Wijs, R. Laskowski, P. Blaha, R. W. A. Havenith, G. Kresse, M. Marsman, J. Chem. Phys. 146, 064115 (2017).]</ref>
</references>
</references>
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[[The_VASP_Manual|Contents]]


[[Category:INCAR]]
[[Category:INCAR tag]][[Category:NMR]][[Category:Chemical shifts]]

Latest revision as of 15:04, 12 December 2022

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.

Related tags and articless

LCHIMAG

References

  1. ↑ G. A. de Wijs, R. Laskowski, P. Blaha, R. W. A. Havenith, G. Kresse, M. Marsman, J. Chem. Phys. 146, 064115 (2017).
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