Hi
I am currently using TURBOMOLE60 program and trying to get the ground state of a donor-acceptor dimmer.
Level of calculation : test single point DFT with 6-31G* basis set.
The default guess (Ext.Huck) ends up by a hole containing electronic configuration. A second calculation with altered occupation in the guess ends up with another double excited state.
Other occupation guesses work even worst.
The same calculations were repeated with other levels :
- the results are correct (real ground state) at HF, B3LYP, PBE0, TPSSh levels, (only with altered order of the EH guess)
- the results are wrong (excited state) at B97-D, PBE, TPSS levels (independently of the initial guess)
Did I miss any particular parameter or procedure which make these calculations work ?
Thank you in advance for your help