[molpro-user] Derivative coupling

[Rameswar Bhattacharjee]

Actually I want to see conical intersection between two different symmetric
states.Is that possible?Please suggest me something.Thank you in
advance.looking for your kind reply.
Regards
Rameswar



On Thu, Jun 26, 2014 at 11:28 AM, Rameswar Bhattacharjee <
rameswarb22 at gmail.com> wrote:

> Thanks for the reply.I understood your suggestion that derivative coupling
> for different symmetric state may be zero.But in many literature I found
> the pseudo jahn teller(PJT) distortion is due to the coupling between
> different symmetric state.So I am thinking that may be it is not zero for
> all case.Here I am using  "CPMCSCF,NACM"method that calculating
> non-adiabetic coupling.Can you suggest me some other  method with CPMCSCFto
> get that coupling term.It will be very helpfull for me.Thank you.
>
> Regards
> Rameswar Bhattacharjee
>
>
>
> On Thu, Jun 26, 2014 at 11:05 AM, Alexander Mitrushchenkov <
> Alexander.Mitrushchenkov at u-pem.fr> wrote:
>
>>  Hi,
>>
>> Maybe the error message is misleading; but it wants to say that the
>> derivative coupling is zero by definition between states of different
>> symmetry, that's why the program refuses to calculate it. It can be easily
>> understood if you remember that coupling is nothing more than the
>> derivative of overlaps at close geometries, which is zero if symmetry is
>> different. If your molecule is not diatomic, and you need couplings for
>> deformations that lower the symmetry (and thus become allowed), you should
>> lower the whole symmetry from the beggining, as Alan also suggested; you do
>> not need in principle to switch it completely off, just remove the symmetry
>> that the required deformation breaks.
>>
>> Hope this helps,
>>
>> Alexander
>>
>> Le 25/06/2014 12:06, Rameswar Bhattacharjee a écrit :
>>
>>   Hi,
>>  I am trying to calculate the derivative coupling between two states
>> namely 1.1 and 2.6. The programs terminates with a message "Non-adiabatic
>> coupling only for same state symmetry". Is there a way, I can calculate the
>> derivative coupling between states of different symmetry in
>> MOLPnon-adiabatic coupling can be calculated between states of the same
>> symmetryRO.
>>
>>  Also, the derivative coupling program does not allow defining
>> frozen/core orbitals (comment: kraft: no frozen core possible with SA_MC)
>> which leads to a very large occupied space for heavy molecules like Ge3H3
>> requiring large memory. Is there a way, we can choose the important
>> (active) orbitals and then do a derivative coupling between states of
>> different symmetry?
>>
>>  Thanking You
>>
>>
>>
>> --
>>
>> ---------------------------------------------------------------------------------------------
>> * "The man who makes no mistakes does not usually make anything."*
>> *                                  Edward John Phelps (1822-1900)*
>>
>> ---------------------------------------------------------------------------------------------
>>
>> Rameswar Bhattacharjee
>> Junior Research Fellow
>> Dept. of Spectroscopy
>> Indian Association for the Cultivation of Science
>> Jadavpur, Kolkata-32
>>
>>
>>
>> _______________________________________________
>> Molpro-user mailing listMolpro-user at molpro.nethttp://www.molpro.net/mailman/listinfo/molpro-user
>>
>>
>>
>> --
>> Dr. Alexander Mitrushchenkov, IGR
>> Laboratoire de Modélisation et Simulation Multi Echelle
>> UMR 8208 CNRS
>> Université Paris-Est Marne-la-Vallée
>> 5 Bd Descartes
>> 77454 Marne la Vallée, Cedex 2, France
>>
>> Phone:    +33(0)160957316
>> Fax:      +33(0)160957320
>> e-mail:   Alexander.Mitrushchenkov at u-pem.fr
>>
>>
>
>
> --
>
> ---------------------------------------------------------------------------------------------
> * "The man who makes no mistakes does not usually make anything."*
> *                                  Edward John Phelps (1822-1900)*
>
> ---------------------------------------------------------------------------------------------
>
> Rameswar Bhattacharjee
> Junior Research Fellow
> Dept. of Spectroscopy
> Indian Association for the Cultivation of Science
> Jadavpur, Kolkata-32
>
>


-- 
---------------------------------------------------------------------------------------------
*"The man who makes no mistakes does not usually make anything."*
*                                  Edward John Phelps (1822-1900)*
---------------------------------------------------------------------------------------------

Rameswar Bhattacharjee
Junior Research Fellow
Dept. of Spectroscopy
Indian Association for the Cultivation of Science
Jadavpur, Kolkata-32
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