Dear All, I am calculating partial density of states of metal organic frame work (Fe-CHNO). I optimized the geometry followed by I performed post processing computation with mentioned IOP and POP = full. I am using B3LYP hybrid functional and Lanl2dz basis for Iron (Fe) metal and additionally I used 6-31g(d) for C, H, N, and O atoms. 1) Can I calculate density of states of degenerate d-orbitals (dxy, dyz, dzx, dx2-y2, dz2) of Fe metal ? 2) While I am looking to output file of Gaussian, I found Gross Orbital Population Analysis as following : Gross orbital populations:
1
1 1 Fe 1S 0.39844
2 2S 2.00069
3 3S -0.03356 Is it negative value also allowed ? If it allows what it signifies ?
4 4PX 2.00102
5 4PY 2.00054
6 4PZ 2.00070
7 5PX 0.10674
8 5PY 0.10490
9 5PZ 0.11135
10 6PX 0.03151
11 6PY 0.03558
12 6PZ 0.02988
13 7D 0 1.23721
14 7D+1 0.79602
15 7D-1 0.95566
16 7D+2 1.18725
17 7D-2 1.09136
18 8D 0 0.26848
19 8D+1 0.21761
20 8D-1 0.22989
21 8D+2 0.23887
22 8D-2 0.25389
Why there exist 22 orbitals for Iron (Fe) metal though it has 16 electrons from Lanl2dz pseudopotential ? Is it due to Lanl2dz basis set which has 22 basis functions ? How can I explain 7D0, 7D+1, 7D-1, 7D+2 and 7D-2. May I equate with d orbitals ((dxy, dyz, dzx, dx2-y2, dz2) ? Thanks in advance Regards
If you are using Mulliken Population Analysis (MPA) negative populations may appear.
Try to change MPA for another population analysis method.
https://www.researchgate.net/publication/229088266_AN_EMPIRICAL_WAY_TO_CORRECT_SOME_DRAWBACKS_OF_MULLIKEN_POPULATION_ANALYSIS
Article An empirical way to correct some drawbacks of mulliken popul...
Please look Ref. 10 of the above paper where you may find an example of "negative" density of states that were interpreted in an absolutely erroneous way. Reagrds.
Thank you Sebastian.
How do I get the occupations of d orbitals ((dxy, dyz, dzx, dx2-y2, dz2). Is there any trick to get information of occupation of any orbitals ?
Regards
Subbu
If you have the overlap and LCAO coefficients matrices you may write a short program to carry out the population analysis you choose step by step. I Really do not know if the equivalence between D0.. and dxy can be done because I do not work with these kings of molecules. Sorry. Regards, Juan
Kindly, can anyone tell me how can plot the density of state (with negative and positive population) from the gaussian output file ??????
Hi Snehasis Bhunia,
Use GaussSum for plotting DOS. To plot DOS you should compute your optimized geometry with above title (POP=FULL IOP(3/33=1,3/36=-1). Then visit following link for further plotting.
http://gausssum.sourceforge.net/GaussSum2.2/Example/index.html
Subrahmanyam Sappati Sir,
I have already used it. But I have not found negative population plot. Negative population can be plot there? another question is there, how can identified the peaks corresponding for what state (s,p, d etc). Kindly, give me a reply...
Then, I do not know exactly how to plot negative population.
For s, p, d states this may be probable answer.
In Groups.txt you have to specify orbitals instead of atoms.
For. e.g.,
orbitals
Fe-s
1-12,23-34,45-56,67-78
Fe-d
13,18
Fe-p
14,19
If you know the above example/solution. Then probably we are waiting for same answer.
Regards
Subrahmanyam Sappati
Your reply would be very helpful to me Subrahmanyam sir. Kindly, can you tell me how can generate Groups.txt file. KIndly give me a short reply..
First of all you have to get information of number of orbitals (see your output from Gaussian). Then according to your desire/necessary make separate groups such as X 1s, X 2p, X 3d and so on. Here you have to provide all orbitals.
Let us suppose you have 10 orbitals in your system. Then
orbitals
X 1s
1-2
X 1p
3-5
Y 2d
6-10
You should not write number of orbital twice (or more than once). You keep the groups.txt in directory created by Gaussum software.
Regards
Subrahmanyam Sappati
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