Ceilidh ... Re^5: Why is the first excited state equal to the third excited state? Mistakes in input files

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Re^5: Why is the first excited state equal to the third excited state? Mistakes in input files

Solntsev Pasha
solntsev@univ.kiev.ua

Dear Patrick.

>For NSTATE, should we be specify the value equal to or greater than the ISTATE value?

Yes.

>What is the state-tracking? What are the negative values used in the state tracking?

Suppose, you have molecule with equilibrium geometry S0 (ground state). You did CIS (nstate=6, for example) and found, that state of interest is state #2 (withing CIS). You can run geometry optimization for that state:

$cis istate=2 nstate=6 mult=1 $end

After optimization you brought your geometry to S2. For the both geometries S0 and S2 the state of interest will be second in order, in presented case. However, if you have flipping of states during S2 optimization the order of states at S0 and S2 is different. Say, state #2 for S0 is #1 for S2. We need some how "watch" our state of interest. By giving negative value for istate=-2 we activate tracking mechanism and CIS code tracks our state #2. Even if we have flipping between states #1 and #2 CIS will do gradient search for your initial state #2 and then #1 after flipping.

If you have some states lying close to your state of interest, it is very recommended to activate state tracking.

Maybe MCSCF wave function will be even better.

Hope this help.
Pavel.

>Regards,

>Patrick

>On Mon Dec 10 '12 8:25am, Solntsev Pasha wrote
>----------------------------------------------
>>Dear Patrick.

>>from manual:

>>NSTATE = � Number of states to be found (excluding the
>> � � � � � ground state).

>>ISTATE = � State for which properties and/or gradient will
>> � � � � � be calculated. Only one state can be chosen.

>>Optimization is a gradient calculation. If you are interesting in 1st state, set istate=1, if 2nd istate=2 etc.

>>I also want to draw your attention to symmetry issue.
>>ISTSYM - symmetry of states of interest. Default is zero, i.e., does not use
>>any symmetry during calculations. Setting this to the desired index of irrep
>>(according to PC GAMESS/Firefly numbering) will solve only for the states of
>>the desired symmetry and exploiting full (including non-abelian) symmetry of
>>molecule, thus significantly reducing computation time.

>>and finally you can activate state-tracking:
>>The state-tracking feature of the PC GAMESS/Firefly' CIS code can be
>>activated by selecting negative value of istate in the $cis group.
>>It is intended for geometry optimization of the excited states in the
>>case of root flipping.

>>Hope this help.
>>Best.

>>Pavel.
>>
>>
>>On Mon Dec 10 '12 4:28am, Patrick SK Pang wrote
>>-----------------------------------------------
>>>Dear Pavel,

>>>I want to make sure the meanings of the values for istate and nstate.
>>>For nstate, 6 is that the progam will give the energy results of the ground state, and the 1st, 2nd, 3rd, 4th, 5th and 6th excited states. Right?
>>>For istate, 1 is the first excited state, but not ground state. For my case, the program will give the optimized geometry of the first exctied state. Right?

>>>Regards,

>>>Patrick
>>>
>>>
>>>On Sun Dec 9 '12 7:35pm, Solntsev Pasha wrote
>>>---------------------------------------------
>>>>Dear Patrick.

>>>>I both cases you requested only one state. It means, you don't have access to higher states.

>>>>For 1-T optimization i would recommend you to use this:
>>>>$CIS nstate=6 istate=1 mult=3 $end
>>>>for 3-T :
>>>>$CIS nstate=6 istate=3 mult=3 $end

>>>>Also, if you have the same symmetry for first and third triplet states, you can use ISTSYM to filter off all states undesired symmetry.

>>>>Good luck.

>>>>Pavel.

>>>>
>>>>
>>>>
>>>>On Sun Dec 9 '12 5:19pm, Patrick SK Pang wrote
>>>>----------------------------------------------
>>>>>Dear all,

>>>>>I think there are mistakes in my input files. It is because the optimized gemoetry and the energy of the first excited triplet state are equal to those of the third excited triplet state. Could you help me to point out the mistakes of my input files? My input files are as follows.

>>>>>First excited triplet state:
>>>>> $CONTRL RUNTYP=Optimize $END
>>>>> $CONTRL SCFTYP=RHF CITYP=CIS $END
>>>>> $CONTRL ICHARG=0 MULT=1 $END
>>>>> $CONTRL NZVAR=33 $END
>>>>> $CONTRL ICUT=20 ITOL=30 INTTYP=HONDO $END
>>>>> $SCF NCONV=10 FDIFF=.FALSE. $END
>>>>> $ZMAT DLC=.T. AUTO=.T. $END
>>>>> $BASIS EXTFIL=.T. GBASIS=acc-pvdz $END
>>>>> $CIS NSTATE=1 ISTATE=2 MULT=3 $END
>>>>> $SYSTEM TIMLIM=10000 MWORDS=100 $END
>>>>> $P2P P2P=.T. DLB=.T. $END
>>>>> $STATPT NSTEP=200 METHOD=GDIIS $END
>>>>> $DATA
>>>>>Molecule specification
>>>>>...
>>>>> $END

>>>>>Third excited triplet state:
>>>>> $CONTRL RUNTYP=Optimize $END
>>>>> $CONTRL SCFTYP=RHF CITYP=CIS $END
>>>>> $CONTRL ICHARG=0 MULT=1 $END
>>>>> $CONTRL NZVAR=33 $END
>>>>> $CONTRL ICUT=20 ITOL=30 INTTYP=HONDO $END
>>>>> $SCF NCONV=10 FDIFF=.FALSE. $END
>>>>> $ZMAT DLC=.T. AUTO=.T. $END
>>>>> $BASIS EXTFIL=.T. GBASIS=acc-pvdz $END
>>>>> $CIS NSTATE=1 ISTATE=4 MULT=3 $END
>>>>> $SYSTEM TIMLIM=10000 MWORDS=100 $END
>>>>> $P2P P2P=.T. DLB=.T. $END
>>>>> $STATPT NSTEP=200 METHOD=GDIIS $END
>>>>> $DATA
>>>>>Molecule specification
>>>>>...
>>>>> $END

>>>>>Thanks!

>>>>>Regards,

>>>>>Patrick

Mon Dec 10 '12 6:56pm

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