pDoS (gaussian basis) output

Just Got Here

9:45:56 AM PST - Fri, Nov 23rd 2012

Hi all,

I have been trying to run pdos calculations for small cationic metal clusters using gaussian basis sets.
With dplot, I produce output files for s, p and d dos, each containing three columns. I think they are supposed to contain the energy, the total dos and the partial dos for the particular orbital.

However, the energy range runs from -16eV to -6eV, when the energy of the HOMO (also calculated) is at about -0.36 eV. I've no idea how to scale the energy range to include the appropriate part. Indeed I'm not sure the energies of the dos calculation even match those of the single point calculation, because the dos spectrum appears (to my eye and from experience) to contain the region around the Fermi energy.

Many thanks if someone has done similar calculations and can show me where I've gone wrong.

Chris
University of Birmingham

start dos_PBE

memory total 2000 mb

charge 1

geometry units angstrom noautoz noautosym
Ag     0.881989760      1.098865390      0.136615940
Ag     2.229498480     -1.157958900      1.109184180
Ag    -0.397261800     -1.348951010      0.150713110
Au    -1.652763890      0.860128030     -0.776872450
end

basis
 Ag library def2-tzvpp
 Au library def2-tzvpp
end

ecp
 Ag library def2-ecp
 Au library def2-ecp
end


dft
 XC xpbe96 cpbe96
 grid xfine
 mult 2
 convergence ncydp 0 dampon 1d99 dampoff 1d-7 damp 70
 iterations 750
 noio
end

driver
 tight
 eprec 1e-7
 clear
 trust 1.0
 maxiter 100
 xyz dos_PBE
end

set lindep:tol 1.0d-7
set int:acc_std double 1d-10
set dft:diisreset 25
unset dft:converged

task dft

dft
 mulliken
 print "mulliken ao"
end

task dft

dplot
dos
vectors dos_PBE.movecs
output dos_s.xy
end

set dplot:dos_doproj t
set dplot:angproj 0

task dplot


dplot
dos
vectors dos_PBE.movecs
output dos_p.xy
end

set dplot:dos_doproj t
set dplot:angproj 1

task dplot

dplot
dos
vectors dos_PBE.movecs
output dos_d.xy
end

set dplot:dos_doproj t
set dplot:angproj 2

task dplot

Forum Vet

12:37:20 PM PST - Mon, Nov 26th 2012

Please send output file

Chris,
Could you please send us either the full output file or just the portion of the PDOS calculation?
It should be something like

 homo eval no.                    38  energy (eV)=  -5.8921675042685129

 homo eval no.                    37  energy (eV)=  -5.8201003989891857

 au extrm  -0.39765161334028609      -3.01396692021016488E-002

 ev extrm   -10.820100398989185      -0.82010039898918585

 no. electrons in energy range          75.00

Just Got Here

10:30:47 AM PDT - Thu, Aug 8th 2013

Having come back to this problem, I see now the HOMO in the pdos output:

[\CODE]

DOS output goes to file dos_s.xy

 dopro  T

 angproj                      0

 homo eval no.                     38  energy (eV)=  -12.3896591716081

 homo eval no.                     37  energy (eV)=  -14.2213952972052

 au extrm  -0.706409235472445      -0.338897291334260

 ev extrm   -19.2213952972052       -9.22139529720522

 no. electrons in energy range          75.00

integrated PDOS           3.74

 DOS output goes to file dos_p.xy

 dopro  T

 angproj                      1

 homo eval no.                     38  energy (eV)=  -12.3896591716081

 homo eval no.                     37  energy (eV)=  -14.2213952972052

 au extrm  -0.706409235472445      -0.338897291334260

 ev extrm   -19.2213952972052       -9.22139529720522

 no. electrons in energy range          75.00

integrated PDOS           0.64

 DOS output goes to file dos_d.xy

 dopro  T

 angproj                      2

 homo eval no.                     38  energy (eV)=  -12.3896591716081

 homo eval no.                     37  energy (eV)=  -14.2213952972052

 au extrm  -0.706409235472445      -0.338897291334260

 ev extrm   -19.2213952972052       -9.22139529720522

 no. electrons in energy range          75.00

integrated PDOS          70.25

[\CODE]

agrees with the evaluation of the MO's in the scf calculation. MO 38 is at -0.455au and the pdos output says -12.3896591716081 eV, which is the same.

My problem now however, is that these numbers for the HOMO do not agree with the value given earlier in the output:

[code]

Non-variational initial energy

     ------------------------------

Total energy =    -548.336437

1-e energy   =   -1742.723191

2-e energy   =     796.012396

HOMO         =      -0.555745

LUMO         =      -0.413072

[\code]

Furthermore, when plotting the dos, though the total number of electrons is correct, the output is pretty surprising. It shows a HOMO-LUMO gap (the difference between MO 38 and MO 39) of 6.1eV. There is agreement between the scf output (the list of vectors and occupations) and the pdos output, but surely this cannot be correct?

Any experience or advice would be extremely welcome, I'm very confused at this point!

Forum Vet

11:38:44 AM PDT - Thu, Aug 8th 2013
Chris, The output you report for HOMo and LUMO values describes the situation at the beginning of the SCF process. Non-variational initial energy ------------------------------ Total energy = -548.336437 1-e energy = -1742.723191 2-e energy = 796.012396 HOMO = -0.555745 LUMO = -0.413072 Therefore, the HOMO and LUMO eigenvalues reported above do not correspond to the eigenvalues at the end of the (converged) SCF process. The PDOS analysis, instead, utilizes the eigenvalues at the end of the SCF process

Just Got Here

9:15:04 AM PDT - Wed, Aug 14th 2013
Thanks for getting back to me. I know now to disregard those pre-scf HOMO LUMO values. The results are still very surprising, with large gaps in the dos with 0 contribution, ridiculous HOMO-LUMO gaps and no peaks in the empty orbitals (conduction band). I think this may be a functional issue (LC-wPBEh), as PBE gives slightly more reasonable results. However, with no documentation for the dos module, it is difficult to explore or solve. For example, I would like to change the range over which the dos is calculated, to extend into the conduction band (the program naturally spans a range which goes to just higher than the HOMO). Is there a way to do this? Thanks, Chris

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