Hi,
Reading the previous emails remind me checking a number of
calculations I did. For my case, I generate Cd pseudopotential with the
following configuration: 4d10 5s2 and core correction. I then used
standard DZP to generate basis (no %block PAO.basis section) in my
calculation
When I look at the output, I found that the program generated DZ
basis sets for 4d, 5s, and SZ for 5p, which is the polarization orbital
(see below). Are those automatically generated basis not good for 4d? Is
there anything I miss? I'd appreciate any comment.
part of the output:
-----------------------------------------------------------------------------------------------
atom: SANKEY-TYPE ORBITALS:
atom: Selected multiple-zeta basis: split
SPLIT: Orbitals with angular momentum L= 0
SPLIT: Basis orbitals for state 5s
SPLIT: PAO cut-off radius determined from an
SPLIT: energy shift= 0.005000 Ry
izeta = 1
lambda = 1.000000
rc = 7.417129
energy = -0.410139
kinetic = 0.337270
potential(screened) = -0.747408
potential(ionic) = -9.152469
izeta = 2
rmatch = 5.997186
splitnorm = 0.150000
energy = -0.348542
kinetic = 0.552560
potential(screened) = -0.901102
potential(ionic) = -9.990383
SPLIT: Orbitals with angular momentum L= 2
SPLIT: Basis orbitals for state 4d
SPLIT: PAO cut-off radius determined from an
SPLIT: energy shift= 0.005000 Ry
izeta = 1
lambda = 1.000000
rc = 4.387621
energy = -0.860629
kinetic = 6.859800
potential(screened) = -7.720429
potential(ionic) = -20.962464
izeta = 2
rmatch = 2.348500
splitnorm = 0.150000
energy = -0.443697
kinetic = 9.457328
potential(screened) = -9.901025
potential(ionic) = -24.055945
POLgen: Perturbative polarization orbital with L= 1
POLgen: Polarization orbital for state 5s
izeta = 1
rc = 7.417129
energy = -0.083172
kinetic = 0.610108
potential(screened) = -0.693280
potential(ionic) = -8.465104
atom: Total number of Sankey-type orbitals: 15
atm_pop: Valence configuration(local Pseudopot. screening):
5s( 2.00)
5p( 0.00)
4d(10.00)
Vna: chval, zval: 12.00000 12.00000
Vna: Cut-off radius for the neutral-atom potential: 7.417129
-----------------------------------------------------------------
end of output
Haitao
Vladimir Timochevski wrote:
Yes, Andrei is absolutely right: Zn is not a good example of using SZ
for semicore - it's d-states overlap with s-band, and therefore should
be more considered as "valence". SZ should be OK for such elements as
As or Ga, where these states are located deeper in energy, and
therefore are more localized. But in any case, as Andrei pointed out,
everything depends on what you would like to obtain, and you should
always check your particular desired quantity for convergence. (I saw
results of big supercell calculations, where people freeze Zn 3d,
putting it in pseudopotential. However, I would not recomment that ...)
Thanks for your comment, Andrei!
Vladimir.
Andrei Postnikov wrote:
On Fri, 26 Jan 2007, Vladimir Timochevski wrote:
| Usually semicore states are quite localized, and from my experience
a SZ-type
| of orbitals is sufficient for them. So, in case of Zn (3d10
semicore states)
| put something like
| %block PAO.Basis
| Zn 2
| n=4 0 2 P
| 0.0 0.0
| 1.0 1.0
| n=3 2 1
| 0.0
| 1.0
| %endblock PAO.Basis
| This will give you 2 4s-orbitals, 3 4p-orbitals, and 5
3d-orbitals. Cutoff
| radii will be generated automatically.
Dear Vladimir:
This is indeed a quite risky advise... of course the final decision
depends on
what you are doing and level of accuracy you need. You'll probably
get the position of Zn3d band right with SZ, but lattice parameter,
elastic propeties, and phonons could be quite off. 3d of Zn is hardly
a good semicore, it is really too close and contribute substantially
to bondings.
Best regards,
Andrei
