Molcas Forum

Hanros

Member

Registered: 2017-12-26

Posts: 17

RASSCF L-edge spectrum

Hi

I am trying to generate a L-edge spectrum of MnSi12+ through RASSCF. I am looking to include the metal 2p orbitals in RAS1 and the 3d metal orbitals in RAS2. The issues is however that there are other orbitals in between these two classes and I'm unsure of how to make them inactive. I have tried the following input, however, I'm getting errors:

Inactive
17 1 2 8 2 8 11 7
RAS1
0 1 1 0 1 0 0 0
Inactive
0 10 12 0 10 0 0 0
RAS2
5 0 0 3 1 3 3 0

Could someone please advise me.

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,011

Re: RASSCF L-edge spectrum

The orbitals are taken in order: frozen, inactive, RAS1, RAS2, RAS3, secondary, deleted. If you wish does not match this, you can rearrange your orbitals by using the ALTER keyword, or you can manually modify the orbital indices in an *Orb file (look for the #INDEX section at the end of it), and use it as input orbitals for RASSCF. What makes no sense is having twice "Inactive" and with different values.

For example, if you want orbital 3 in RAS1, orbitals 14-16 in RAS2 and orbitals 1-2,4-13 inactive, you'd say:

Inactive = 12   * 12 orbitals in total
RAS1 = 1
RAS2 = 3

and you'd have to move orbital 3 to position 13, or swap orbitals 3 and 13:

Alter = 1   * 1 swap
1 3 13      * swap orbitals 3 and 13 of symmetry 1

Or in the *Orb file you'd have something like:

#INDEX
* 1234567890
0 ii1iiiiiii
1 iii222ssss

(i=inactive, 1=RAS1, 2=RAS2, s=secondary)

Hanros

Member

Registered: 2017-12-26

Posts: 17

Re: RASSCF L-edge spectrum

Hi Ignacio

Thank you very much for the reply. I have implemented what you have said, and it seems to be working. However I'm getting the following orbital optimisation problems :

Warning: In symmetry  2, orbital p=  12 has diagonal density matrix element D(p,p) close to two. (2 - D(p,p))=  0.269195D-08

orbital p =12 is one of the orbitals I have swapped and i'm getting similar problems for the other orbitals

Could you kindly advise me on how to overcome this.