Dear All,

(1) I normally set the basis manually and then optimize both the
Cut-off radius of the
first zeta and split norm parameter. However, in most of the optimized
bases available
on the Siesta site has the soft-confinement potential optimized besides the
Cut-off radius. However, I do not turn on the  soft-confinement option
and use the
default setting of "PAO.Soft.Default = false" (Default). So, is it
correct to perform
basis optimization without using the confinement potential ? I optimize the
split-norm parameter for each angular momentum channel. Please advise.

Here is the TZP basis set I optimized for Carbon in the solid-state calculation
(Contains diffuse function too). The Corresponding pseudo (GGA-PBE) was
generated with the same cut-off of 1.52 for all channels ( 2S, 2P, 3D, 4F).

Siesta - 364 was used for the calculation.

%block PAO.Basis
C        4
 n=2   0   3 P 1   S  0.65
   7.000      0.000    0.000
   1.000      1.000    1.000
 n=2   1   3 P 1   S  0.45
   7.000      0.000     0.000
   1.000      1.000     1.000
n=3   2   1        S  0.15
  7.00000
  1.00000
n=3   0   1        S  0.15
  8.00000
  1.00000
%endblock PAO.Basis

(2) Do the Optimized values (here, the split-norm parameter) change if
the I change the exchange-correlation ? Say for example If I use
VDW-DRSLL instead of PBE ?

(3) For the same exchange-correlation, if I change the size of the
first zeta orbital (Here, 7.0), do I have to reoptimize the basis ?

Thank you

-- Madan
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Madan Mithra .L.M
Senior Research Fellow
Dept.of Physics
Indian Institute of Science
Bangalore - 560 012
INDIA
.........................................
Phone : 91-80-22932313 (Lab)
 FAX   : (080) 360 2602
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