OK. Now I understand.
Thank you.
Best regards,
/Guangping
On 04/27/2015 07:02 PM, Pu ZHANG wrote:
I'm not familiar with SIESTA, but in case some electrons might
contribute to the interested energy range, however they are too
expensive to consider explicitly, like the d wlwcteons of noble
metals. Phenomenological description is an approximation. This is what
I meant.
On Tuesday, April 28, 2015, Guangping Zhang <[email protected]
<mailto:[email protected]>> wrote:
Dear Pu Zhang,
As far as I know, the Drude term in SIESTA is omega_p*omega_p, and
the Drude contribution to the dielectric function is added by the
simple Drude model,
-omega_p*omega_p/omega/(omega+i*gamma)
where i is the imaginary unit. Therefore, Drude term used in
SIESTA is to account for the effect of the free electrons.
However, for cluster in SIESTA, all the transitions from occupied
to unoccupied orbitals are taken into account in the interested
energy range. I think this would include the 'free electrons' and
the 'bound electrons' in the energy range in the current framework
in SIESTA.
So, what do you mean by "a contribution from deeper transitions",
could you please give more information on this?
/Guangping
On 04/27/2015 05:11 PM, Pu ZHANG wrote:
I suppose the so-called intraband contribution is just the part
of the permittivity which is not described by the simple Drude
model. Then it doesn't necessarily apply to bulk material. For
cluster it can also get contribution from deeper transitions. I
guess it's possible to implement this somehow...
Best regards, Pu Zhang
--
Faculty at School of Physics, Huazhong University of Science and
Technology
Room 819 (N.), Yifu Science and Technology Building
1037 Luoyu Road, Wuhan, China
E-mail: [email protected]
<javascript:_e(%7B%7D,'cvml','[email protected]');>
Homepage: www.researchgate.net/profile/Pu_Zhang4
<http://www.researchgate.net/profile/Pu_Zhang4>
Phone: +86 18871860394
On Mon, Apr 27, 2015 at 9:34 PM, Guangping Zhang <[email protected]
<javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote:
Dear Eliya,
For a cluster, I think there is no energy bands, therefore no
intraband transition.
/Guangping
On 2015/4/27 14:43, Eliya Asmani wrote:
Dear Guangping
Thanks for the your quick reply.
As I know the intarband transition (Drude term) is very
important for my case.
I'm so sorry! What is your mean about "Drude term is only
for a system with at least one dimension periodical" you
mean the Siesta code can't calculate for cluster system or
Drude term is not important in cluster system?
Eliya
On Mon, Apr 27, 2015 at 4:21 PM, Guangping Zhang
<[email protected]
<javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote:
Dear Eliya,
I think you do not need to include the Durde term for a
cluster calculation. The Drude term is only available
for a system with at least one dimension periodical.
Kind regards,
/Guangping
On 04/27/2015 12:44 PM, Eliya Asmani wrote:
Dear user
I want to calculate real and imaginary parts of the
permittivity for some metals
(for cluster not bulk).
How can I include Drude term for intarband transition
of the permittivity?
In the *.EPSIMG, (was generated after optical
calculation) the value of W_p is written 0.000. I think
this value should be non-zero, to include Drude term.
How can I determinate W_p?
Regards,
Eliya
--
Best regards, Pu Zhang
--
Faculty at School of Physics, Huazhong University of Science and
Technology
Room 819 (N.), Yifu Science and Technology Building
1037 Luoyu Road, Wuhan, China
E-mail: [email protected] <mailto:[email protected]>
Homepage: www.researchgate.net/profile/Pu_Zhang4
<http://www.researchgate.net/profile/Pu_Zhang4>
Phone: +86 18871860394
