We use Biovia Material Studio (at time version 2021), and at time mostly Dmol3. Calculations on CHNO molecules but also with higher elements as P. Mostly we use the basis-set DNP and functional B3LYP.

We encountered a feature, which we not understand: The level of orbitals with CNO is in outmol given with one more d-orbital (polarization purpose) than given in the explanation for Dmol3.

This is standard: C, N, O:    1s 2s 2p 2s' 2p' 3d

But in outmol:      C, N, O:   1s 2s 2p 2s' 2p' 3d  3d' 

With P element, one has again the standard: 1s 2s 2p 2s' 2p' 3d

In outmol appears for 3d' the remark: 'eliminated'. What does this mean?

We have the impression Dmol3 calculates with additional 3d' and then it discards it?

Why 3d’ is included then? Is this an error?

How is the situation when using dispersion correction as Grimme