I need some help to setup a constrained DFT calculation: In particular, I want a DFT-single point calculation of Ar+ where all 3p-orbitals are degenerate (one is virtual and therefore has considerably higher energy in DFT) and according to my understanding, the CDFT-CI is exactly meant for this.
From the manual I understand it like this: I have three configurations which should contribute equally much, so the
cdft-section should have the form
$cdft STATE_1_CONSTRAINT_VALUE_X 0.333 1 1 TYPE1_X ----- STATE_1_CONSTRAINT_VALUE_X 0.333 1 1 TYPE1_X ----- STATE_1_CONSTRAINT_VALUE_X 0.333 1 1 TYPE1_X $end
First: Is the coefficient 1/3 or should it be 1/sqrt(3)? Than, I have as first and last atom the ‘1’.
Each state is specified with the CONSTRAINT_VALUE and the corresponding weights on sets of atoms whose average value should be the constraint value
I am here irritated by the
type and the
constraint_value. What do I put there to specify the correct state? I’d think that I should tell it somehow that the ground, first and second excited states are relevant here?
Many thanks in advance for all kind of help