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Re^6: Regarding the TDDFT state tracking feature....

Alexei Popov
alexei.a.popov@gmail.com


Hi,

>Thanks for the information. Does this mean that state 3 has become state 2 now?
Exactly

> Also Alexei, I hope there is no way to predict this state flipping?
It is not possible to predict this flipping a priori.

> It is certainly dependent on the code.
This does not depend on the code.

> I mean I run for ISTATE=1, then it doesnt mean that first state
> will be flipped or something like that?
It is possible under some circumstances.

>Sir if this flipping occurs in the geometry optimization of S1 state,
>then what should I do? Because I just optimize this state and then
>directly use the S1 geometry for finding S1 to S0 transitions.
In this situation, you can try to optimize S1 state using different starting geometry.

-Alexei



On Sat Oct 25 '14 2:23pm, Siddheshwar Chopra wrote
--------------------------------------------------
>Dear Alexei,
>Thanks for the information. Does this mean that state 3 has become state 2 now? Also Alexei, I hope there is no way to predict this state flipping? It is certainly dependent on the code. I mean I run for ISTATE=1, then it doesnt mean that first state will be flipped or something like that?

>Sir if this flipping occurs in the geometry optimization of S1 state, then what should I do? Because I just optimize this state and then directly use the S1 geometry for finding S1 to S0 transitions.

>Kind Regards,
>
>
>On Sat Oct 25 '14 2:11am, Alexei Popov wrote
>--------------------------------------------
>>Hi,

>>look at warnings like this one:

>> WARNING: STATE FLIPPING OCCURED.
>> FIREFLY HAS FOLLOWED STATE 3, NOW FOLLOWS STATE 2 WITH OVERLAP OF 0.812345

>>-Alexei
>>
>>
>>On Fri Oct 24 '14 8:09pm, Siddheshwar Chopra wrote
>>--------------------------------------------------
>>>Dear Alexei,
>>>Unfortunately I don't know about them. I right now wish to know how should I resolve this state flipping. Please tell me how to do it from the output file with state tracking on.

>>>Kind Regards,

>>>On Fri Oct 24 '14 2:25am, Alexei Popov wrote
>>>--------------------------------------------
>>>>Hi,

>>>>Do you know something on avoided crossings and conical intersections?Tracking helps with getting the same diabatic states over large areas of complex PES with state crossings.

>>>>-Alexei
>>>>
>>>>
>>>>On Thu Oct 23 '14 9:40pm, Siddheshwar Chopra wrote
>>>>--------------------------------------------------
>>>>>Dear All,
>>>>>Somebody please elaborate on the use of state tracking feature in TDDFT calcs. I just know how to turn it on. But exactly how does it help me in bring the excited states in correct order? Please help. I really need to learn this.

>>>>>Kind Regards,
>>>>>
>>>>>
>>>>>On Fri Oct 17 '14 7:58am, Siddheshwar Chopra wrote
>>>>>--------------------------------------------------
>>>>>>Dear Users,
>>>>>>I need your help regarding the state flipping in TDDFT calculations. I switch on the state tracing feature in S1 optimization. As far as I have read there is possibility of excited states getting mixed up or flipped. But I really don't know how to figure out this  state flipping and determine the correct order of states. Somebody please help me in understanding this.
>>>>>>OR Do I just check each energy level's TOTAL energy and figure out the order? Is it correct?
>>>>>>I would be grateful if anyone could explain right from the UV till emission calculations.

>>>>>>Kind Regards,


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