With this type of project, you can calculate the interaction energy of a
system built out of two subsystems. The interaction energy is computed as
the difference between the energy of the two non-relaxed subsystems.
An Interaction energy project starts defining the two atomic structures of
the subsystems. We refer the user to section Structure Modeling in ASAP for further information
on the ASAP structure builder/viewer interface.
The definition of the subsystems is done by fixing the atoms of one of the
two subsystems and releasing the atoms of the other. This can be done on an
existing project (Fig. 7)
or by merging two structures of two
projects (section Merge two structures).
Fig. 7 Procedure to fix atoms in the atomic structure.#
Once the structure is ready edit the type of the project by selecting
Interaction energy from the list of possible project types implemented in
ASAP.
A window will appear showing the composition of the interface:
Press the Yes button to proceed.
Click on the Parameters icon to open the Interaction energy parameters
widget. From the Parameters widget you can chose to compute,
Interaction energy with counterpoise correction (Default): The
interaction energy is computed as,
\(E(AB)_{ab}\) is the energy of the whole system \((AB)\),
\(E(A)_{ab}\) and \(E(B)_{ab}\) are the energy of the first and
second subsystems, respectively, computed using a mixed basis set (ghost
atoms).
Interaction energy: The interaction energy is computed as,
\(E(AB)_{ab}\) is the energy of the whole system \((AB)\),
\(E(A)_{a}\) and \(E(B)_{b}\) are the energy of the first and
second subsystems, respectively.
In the bottom part of the Parameters widget, you can select which system
you want to visualise and the orientation,
Press the Ok button to close the IET widget once the parameters are
properly set.
Click on the SIESTA_4.1 (calculator) icon to select SIESTA input
parameters. Notice that the SIESTA is the only calculator available for the
Interaction energy project.
Click on the Run icon to open the Run widget. Then press the Run
button to submit the Interaction energy calculation.
We refer the user to chapter Runners for further information on computational
resources configuration in ASAP.
While the calculation is running the Run widget shows the calculation
output in real time.
