[Wien] excited state of a system

[shamik chakrabarti]

Dear Stefaan Sir,

                         Thank you very much for clearing all of my
doubts....Thank you very much Sir.

with best regards,

Shamik Chakrabarti

On Thu, May 6, 2010 at 4:34 PM, Stefaan Cottenier <
Stefaan.Cottenier at ugent.be> wrote:

>
> > But is your reply indicating that.......
>
>>
>> the excited states *may be* those states having higher energy....but it is
>> *not sure* that whether the states having higher energy will be the excited
>> states of the system??......Please assure me that this is the meaning of
>> your reply...........
>>
>
> Yes.
>
>
>  but if this is the meaning then another question is that may it be
>> happened that some converged solutions of the system actually never be found
>> in reality??...
>>
>
> Sure. You examined only ferromagnetic, antiferromagnetic and 'non-magnetic'
> states. But for sure there are many more magnetic configurations for which
> you can get a converged solution. And the same holds also for the structural
> degrees of freedom: you will find converged solutions for your solid in e.g.
> bcc, fcc, ... crystal structures. No way to find all these many situations
> if you increase the temperature.
>
>
>  if this is true then the question is why?
>>
>
> Many possible reasons:
>
> * all calculated information is at 0 K. Phonons and all kinds of electronic
> excitations will enter the game at temperatures above 0 K, and these might
> alter the picture.
> * something else might have happened before (e.g. a structural phase
> transition occurs before you reach the point where a magnetic phase
> transition in the original material would have occurred)
> * some solutions correspond to saddlepoints, and will spontaneously evolve
> to another solution
> * your material might be molten before you reach the energy corresponding
> to a particular case
> *...
>
>
> Stefaan
>
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-- 
Shamik Chakrabarti
Research Scholar
Dept. of Physics & Meteorology
Material Processing & Solid State Ionics Lab
IIT Kharagpur
Kharagpur 721302
INDIA
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