input for O(3P) and O(1D) atom

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Alex_Novosibirsk
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Joined: 07 Dec 2015, 22:46
First name(s): Alexey
Last name(s): Chichinin
Affiliation: Institute fur Physicalische und Theoretische Chemie, Braunschweig
Country: Germany

input for O(3P) and O(1D) atom

Post by Alex_Novosibirsk » 13 Dec 2015, 23:31

Dear collegues, excuse me in advance for asking, probably, stupid questions, because I'm new in Dalton.
I tried to obtain energy of oxygen atom O(3P) and O(1D), but failed. For example, my single-input file is:
--------------------------
BASIS
cc-pVDZ
O-atom symmetries in D2h are: 3Pg: 4,6,7 1Dg: 1,1,4,6,7, 1Sg:1

1
8. 1
O .0 .0 .0


**DALTON
.RUN RESPONSE
**WAVE FUNCTIONS
.HF
.MP2
*SCF INPUT
.DOUBLY OCCUPIED
2 0 0 1 0 0 0 0
.SINGLY OCCUPIED
0 0 0 0 0 1 1 0
**END OF
---------------------------------------
gives in output file:

@ Spin multiplicity: 3
@ Spatial symmetry: 4 ( irrep B1g in D2h )
@ Final HF energy: -63.256994617873

this HF energy is very far from the energy of the ground state of the oxygen atom (near -74.7 a.u.). What is wrong?
best wishes, Alexey Chichinin

olav
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Re: input for O(3P) and O(1D) atom

Post by olav » 14 Dec 2015, 07:34

Did you that check the orbitals in the output?You will most likely find that your open-shell orbitals are not p-orbitals, but d-orbitals.
The p-orbitals show up in the ungerade symmetries (by default usually 2, 3, 5)

Regads,
Olav

taylor
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Re: input for O(3P) and O(1D) atom

Post by taylor » 14 Dec 2015, 08:13

Olav has already answered and is certainly correct: can I suggest also that you look at the detailed manual section on symmetry in Dalton (disclaimer: I wrote it...)? The comment in your input about the irreps for the O states is correct only for the many-electron states, 3Pg and 1Dg. But in the SCF input you specify the symmetry of the individual orbitals that comprise your open shells, not the overall symmetry of the state.

Best regards
Pete

Alex_Novosibirsk
Posts: 2
Joined: 07 Dec 2015, 22:46
First name(s): Alexey
Last name(s): Chichinin
Affiliation: Institute fur Physicalische und Theoretische Chemie, Braunschweig
Country: Germany

Re: input for O(3P) and O(1D) atom

Post by Alex_Novosibirsk » 14 Dec 2015, 23:46

Dear Olav, dear Pete, thank you very much for your very informative reply. Now I can make a single-input files to obtain O-atom properties. Here is one of them:

BASIS
cc-pVDZ
O-atom symmetries in D2h: 3Pg:4,6,7; 1Dg:1,1,
4,6,7; 1Sg:1. Single Pu orbital is 2,3,5.
Atomtypes=1
8. 1
O .0 .0 .0

**DALTON
.RUN RESPONSE
**WAVE FUNCTIONS
.HF
.MP2
*SCF INPUT
.DOUBLY OCCUPIED
2 1 0 0 0 0 0 0
.SINGLY OCCUPIED
0 0 1 0 1 0 0 0 0
**END OF

I made all possible combinations of doubly/singly occupied orbitals and obtained the results:

Doubly: 21000000 Singly: 00101000 -> 3Xg, Sym=7, E=-74.7861742664
Doubly: 20001000 Singly: 01100000 -> 3Xg, Sym=4, E=-74.7875130746
Doubly: 20100000 Singly: 01001000 -> 3Xg, Sym=6, E=-74.7861742664
Doubly: 21100000 Singly: 00000000 -> 1Xg, Sym=1, E=-74.665278726428
Doubly: 20101000 Singly: 00000000 -> 1Xg, Sym=1, E=-74.665278726428
Doubly: 21001000 Singly: 00000000 -> 1Xg, Sym=1, E=-74.665278726428

First three solutions are ground state triplet, they have correct symmetry and are evidently O(3P).
The next three solutions have the same energy, spin, symmetry, and they are higher 3P by
0.1208955*27.2116= 3.29 eV. I can not understand what they mean.
(I also don't know, where in *.out file to read orbital moment of the atom (S, P, or D?) )
Note that in oxygen \Delta E ( 1D-3P)= 2 eV, and \Delta E(1S-1D)= 2 eV, and hence the 3 states of symmetry=1
can not have the same energy.
Then I proposed to Dalton to find correct states by CAS SCF:

BASIS
cc-pVDZ
O-atom symmetries in D2h: 3Pg:4,6,7; 1Dg:1,1,
4,6,7; 1Sg:1. Single Pu orbital is 2,3,5.
Atomtypes=1
8. 1
O .0 .0 .0

**DALTON
.RUN WAVE FUNCTIONS
**WAVE FUNCTIONS
.MCSCF
*CONFIGURATION INPUT
.SYMMETRY
1
.SPIN MULTIPLICITY
1
.INACTIVE ORBITALS
2 0 0 0 0 0 0 0
.ELECTRONS
4
.CAS SPACE READ
0 1 1 0 1 0 0 0
*POPULATION ANALYSIS
.ALL
**END OF DALTON INPUT

and obtained 1Xg symmetry=1, Final MCSCF energy: -74.705522205724, which is 2.2 eV above the ground state O(3P). I like to think that I have obtained here O(1D), because of correct energy, but I don't know if I am right.
But why it have not found ground state O(3P)?
Help me please, how to obtain O(1D) energy and wave functions?
Also, what should I add in last scropt to see properties of all excited states ?
Best wishes, Alexey

taylor
Posts: 545
Joined: 15 Oct 2013, 05:37
First name(s): Peter
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Affiliation: Tianjin University
Country: China

Re: input for O(3P) and O(1D) atom

Post by taylor » 15 Dec 2015, 08:26

With Dalton you specify the spin multiplicity for the state of interest in your CASSCF calculation, as you have done by explicitly choosing the multiplicity 1. This is a singlet in you (that is, what you specify is 2S+1, where S is the total spin, not just the M_S value). If you want to get the components of the 3P state, you must specify the spin multiplicity as 3. Thus the 3P and 1D will need to be done in two separate calculations.

By the way, these "CAS" calculations are single configurations, and since no correlation at all is included one would expect, as is typical with Hartree-Fock, that higher multiplicity states will be favoured. Hence you should expect the 1D state to come out somewhat further above 3P than is observed in nature.

Best regards
Pete

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