NLSPLINE: Difference between revisions

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Description: construct the PAW projectors in reciprocal space using spline interpolation so that they are ''k''-differentiable.
Description: construct the PAW projectors in reciprocal space using spline interpolation so that they are ''k''-differentiable.
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For {{TAG|NLSPLINE}}=.TRUE., the PAW projectors in reciprocal space ({{TAG|LREAL}}=.FALSE.) are set up using a spline interpolation so that they are ''k''-differentiable. This only slightly affects the chemical shifts themselves, but can have impact on the susceptibility contribution (the aforementioned Eq. 47). It is advised to set {{TAG|NLSPLINE}}=.TRUE., only in case of chemical shift calculations. Since this option also gives slightly different total energies, it is advised to use the default {{TAG|NLSPLINE}}=.FALSE. for compatibility in all other calculations.  
For {{TAG|NLSPLINE}}=.TRUE., the PAW projectors in reciprocal space ({{TAG|LREAL}}=.FALSE.) are set up using a spline interpolation so that they are ''k''-differentiable. This improves the susceptibility contribution to the chemical shifts. It only slightly affects the other contributions to the chemical shifts.


Real space projectors ({{TAG|LREAL}}≠.FALSE.) are ''k''-differentiable by construction.
It is advised to set {{TAG|NLSPLINE}}=.TRUE. if and only if PAW projectors are applied in reciprocal space and chemical shifts are are calculated, i.e. if and only if {{TAG|LREAL}}=.FALSE. and {{TAG|LCHIMAG}}=.TRUE. As this option also gives slightly different total energies, it is advised to use the default {{TAG|NLSPLINE}}=.FALSE. in all other calculations for reasons of compatibility.
 
Real space projectors are ''k''-differentiable by construction, hence do not require to set {{TAG|NLSPLINE}}=.TRUE.


== Related Tags and Sections ==
== Related Tags and Sections ==

Revision as of 16:44, 26 February 2020

NLSPLINE = .TRUE. | .FALSE.
Default: NLSPLINE = .FALSE. 

Description: construct the PAW projectors in reciprocal space using spline interpolation so that they are k-differentiable.


For NLSPLINE=.TRUE., the PAW projectors in reciprocal space (LREAL=.FALSE.) are set up using a spline interpolation so that they are k-differentiable. This improves the susceptibility contribution to the chemical shifts. It only slightly affects the other contributions to the chemical shifts.

It is advised to set NLSPLINE=.TRUE. if and only if PAW projectors are applied in reciprocal space and chemical shifts are are calculated, i.e. if and only if LREAL=.FALSE. and LCHIMAG=.TRUE. As this option also gives slightly different total energies, it is advised to use the default NLSPLINE=.FALSE. in all other calculations for reasons of compatibility.

Real space projectors are k-differentiable by construction, hence do not require to set NLSPLINE=.TRUE.

Related Tags and Sections

LCHIMAG, DQ, ICHIBARE, LNMR_SYM_RED

Examples that use this tag