Energy Decomposition Analysis

In BAND there are two fragment-based energy decomposition methods available: the periodic energy decomposition analysis (PEDA) [1] and the periodic energy decomposition analysis combined with the natural orbitals of chemical valency method (PEDA-NOCV) [1].

Periodic Energy Decomposition Analysis (PEDA)

PEDA Yes/No
PEDA
Type:Bool
Default value:No
Description:If present in combination with the fragment block, the decomposition of the interaction energy between fragments is invoked.

If used in combination with the fragment keyblocks the decomposition of the interaction energy between fragments is invoked and the resulting energy terms (\(\Delta E_{int}\), \(\Delta E_{disp}\), \(\Delta E_{Pauli}\), \(\Delta E_{elstat}\), \(\Delta E_{orb}\)) presented in the output file. (See the example or the tutorial)

Attention

In case of the error message “Fragments cannot be assigned by a simple translation!”, BAND does only allow for fragments which can be transformed to the structure in the PEDA calculation by a simple translation. So, a rotation is not allowed.

Periodic Energy Decomposition Analysis and natural orbitals of chemical valency (PEDA-NOCV)

PEDANOCV (block-type)

If present in combination with the fragment keyblocks and the PEDA key the decomposition of the orbital relaxation term is performed. The binary result file will contain the information to plot NOCV Orbitals and NOCV deformation densities.

See also

PEDANOCV
   EigvalThresh float
   Enabled Yes/No
End
PEDANOCV
Type:Block
Description:Options for the decomposition of the orbital relaxation (pEDA).
EigvalThresh
Type:Float
Default value:0.001
GUI name:Use NOCVs with ev larger than
Description:The threshold controls that for all NOCV deformation densities with NOCV eigenvalues larger than EigvalThresh the energy contribution will be calculated and the respective pEDA-NOCV results will be printed in the output
Enabled
Type:Bool
Default value:No
GUI name:Perform PEDA-NOCV analysis
Description:If true in combination with the fragment blocks and the pEDA key, the decomposition of the orbital relaxation term is performed.

References

[1](1, 2) M. Raupach and R. Tonner, A periodic energy decomposition analysis method for the investigation of chemical bonding in extended systems, The Journal of Chemical Physics 142, 194105 (2015).