Using flip to define a biradical orbital

[fcdestro]

Hello!
I'm trying to use the flip option to treat a biradical species, as to mix HOMO/LUMO orbitals (the poor man’s MC-SCF)
Trying to follow the manual, I performed a first single point calculation at the triplet state, and then I tried to load the control file of this triplet calculation to flip my orbitals. It is able to find my original orbitals, even though it give me some warnings for the occupation numbers:
"""
W A R N I N G : <phi(i)|phi(i)> is   1.00000000000568      for i =
                     1
 W A R N I N G : <phi(i)|phi(i)> is   1.00000000000468      for i =
                     7
 W A R N I N G : <phi(i)|phi(i)> is   1.00000000001299      for i =
                     8

"""
Then, when I try to flip, I have the following error message:
"""
flip

 reading orbital data $uhfmo_alpha  from file alpha
 orbital characterization : expanded

 self consistent orbitals required


 reading orbital data $uhfmo_beta  from file beta
 orbital characterization : expanded

 self consistent orbitals required
"""

Can you help me?
Thank you!
Fabiola

[uwe]

Check the first line of your alpha and beta file. The first line is showing the status of the orbitals.

scfconv=7    are converged MOs with an energy convergence of 10^-7 Hartree
scfdump=31 are non-converged MOs after 31 SCF iterations (the orbitals are only printed to disk in each iteration if $scfdump is in the control file)
expanded     those are start orbitals

Your output says:
orbital characterization : expanded
So they seem to be start orbitals?

[fcdestro]

Thank you for the fast answer!!
They start with the expanded word, I will try to relaunch the scf to see if I get converged orbitals.

Thank you, I will let you know if it works!

Fabiola

[uwe]

Hello,

just as an option (depending on how old your Turbomole version is, check the documentation - the pdf file in $TURBODIR/DOC):

$atomdens

can be used to generate start orbitals from superposition of atomic densities. There you have the options to set partial charges on individual atoms and (for two-component calculations) set the direction of spins for atoms.

Do not use define for that, just add the keyword with all options you want (see documentation) and run ridft.

Good luck, Uwe

[fcdestro]

Hi,

I tried again with converged orbitals, but I still have the same problem with flip. It says it is expanded, even though when I check the file, it has the "scfconv=6" at the beginning.
I think $atomsdens may be better, I checked, and my version has it.
In this case, how can I set the spin directions for atoms? Because in the documentation, there are only examples for defining charges

Thank you
Fabiola