# Akm parameters for D3 (or other unusual) point group

asked by Maximilian Kusch (2023/01/30 14:46)

Dear all,

I am trying to implement a D3 crystal field, but the function PotentialExpandedOnClm seems not to have that. Is that possible and is there another way to extract these parameters?

Thank you for your help! Maximilian

## Answers

Dear Maximilian Kusch,

Indeed the function

PotentialExpandedOnClmis only implemented for a few high symmetry groups in standard orientations. While implementing the lower symmetries I noticed that one does not only need functions for the 32 some point groups, but for each point group also in different orientations. For groups where the d or f orbitals have several states belonging to the same irreducible representation the input became quite arbitrary and non-intuitive.The alternative you can find here: https://www.quanty.org/physics_chemistry/point_groups You first need to select a point group For example https://www.quanty.org/physics_chemistry/point_groups/d3d For a given group you then need to select an orientation / setting. The website shows in pictures what the symmetry axis in x, y, and z coordinates are For example the D3d group with the C3 axis in the z direction and one of the C2 axis in the x direction https://www.quanty.org/physics_chemistry/point_groups/d3d/orientation_zx When you scroll down you find a section potentials for d orbitals (or potentials for f orbitals). If you expand this you find the input you can use in Quanty For the d orbitals

The definitions of the parameters you can find on the website where you also find the expansion.

Hope this helps. Best wishes, Maurits