From NWChem
Viewed 2667 times, With a total of 4 Posts

Just Got Here
Threads 2
Posts 3


3:35:01 PM PST  Fri, Dec 30th 2011 

Hi, all
The following is from my output of tddft calculation,
Root 4 singlet a 0.047664078 a.u. ( 1.2970061 eV)

Transition Moments X 0.64251 Y 0.44088 Z 0.33579
Transition Moments XX 6.00038 XY 4.27193 XZ 1.44530
Transition Moments YY 2.80721 YZ 1.45076 ZZ 2.02436
Transition Moments XXX 68.01522 XXY37.76077 XXZ 9.39828
Transition Moments XYY 70.00061 XYZ 10.52811 XZZ 0.31881
Transition Moments YYY112.60149 YYZ 1.44061 YZZ 16.25681
Transition Moments ZZZ28.04103
Dipole Oscillator Strength 0.02288
Occ.214 a  Virt.218 a 0.17724 X
Occ.214 a  Virt.219 a 0.06488 X
Occ.215 a  Virt.218 a 0.65800 X
Occ.215 a  Virt.219 a 0.07690 X
Occ.215 a  Virt.220 a 0.05800 X
Occ.216 a  Virt.218 a 0.44676 X
Occ.216 a  Virt.219 a 0.22180 X
Occ.217 a  Virt.218 a 0.10449 X
Occ.217 a  Virt.219 a 0.45821 X
Occ.217 a  Virt.220 a 0.17993 X
Occ.217 a  Virt.221 a 0.09552 X
My understanding is, in Root 4, it means, one electron in occupied state 214 is excited to virtual state 218, and so on.... But, why there are 3 transitions started from 215? There should be only 2 electrons in this occupied state. And why there are also more than 2 transitions arrive to the final state listed above.
Maybe my question sounds silly, but would anyone please teach me? Or tell me which book I should look into. Also, what does the last number mean in these lines? Transition moments related with each single excitation?
Thanks in advance.




Niri Forum:Admin, Forum:Mod, NWChemDeveloper, bureaucrat, sysop


Forum Regular
Threads 4
Posts 205


5:07:26 PM PST  Wed, Jan 4th 2012 

Hi,
It's not a silly question at all. Those are not 3 transitions from 215 but the dominant
components of the transition vectors X and Y. Take a look at reviews by Casida on LRTDDFT.
Let me know if you need further clarification.
Best regards,
Niri
niri.govind@pnnl.gov





7:59:30 AM PST  Wed, Feb 1st 2012 

tddft

i am doing a single point in tddft, but the roots are disorder (i think). I am interested in the optically allowed transitions and i will add the the keyword SYMMETRY but i do not understand the keyword TARGETSYM; the manual say TARGETSYM must be specified when SYMMETRY is invoked" . Can someone help me?





8:01:03 AM PST  Wed, Feb 1st 2012 

sorry

I am Lex from Mexico
alexpiedras@gmail.com
regards





10:37:15 AM PST  Wed, Feb 1st 2012 

TRAGETSYM is defined in the manual just above the symmetry description. If you are going to limit the excitation space to a certain symmetry by setting the SYMMETRY keyword you need to specify the irreducible representation of the symmetry of state(s) you're interested in. For example A1g, T2g, etc. Hence, you need to know what the point group symmetry of your molecule is and the state symmetry label (you can look it up in a standard text book).
Bert
Quote: Feb 1st 2:59 pmi am doing a single point in tddft, but the roots are disorder (i think). I am interested in the optically allowed transitions and i will add the the keyword SYMMETRY but i do not understand the keyword TARGETSYM; the manual say TARGETSYM must be specified when SYMMETRY is invoked" . Can someone help me?



AWC's:
2.5.10 MediaWiki  Stand Alone Forum Extension
Forum theme style by: AWC