# Energy Decomposition Analysis¶

In BAND there are two fragment-based energy decomposition methods available: the periodic energy decomposition analysis (PEDA)[56] and the periodic energy decomposition analysis combined with the natural orbitals of chemical valency method (PEDA-NOCV)[56].

## Periodic Energy Decomposition Analysis (PEDA)¶

PEDA [True | False]

PEDA
Type: Bool False 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.

PEDANOCV

PEDANOCV
EigvalThresh
Enabled