Spin of excited states from TDDFT


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Dear NWChem community,

I would like to calculate the spin two (so multiplicity 5) excited states of a molecule, i.e. neither singlets nor triplets. In order to do this, I tried performing a singlet or triplet calculation, starting from a multiplicity 5 configuration. An example input file:

start TT_triplets

memory total 4000 mb

echo

GEOMETRY noautosym noautoz nocenter
C -4.36227857 -2.89231509 -4.35034344
C -4.36158698 -1.48222381 -4.35041529
C -3.51152933 -0.78490047 -3.50258695
C -2.63573885 -1.47163765 -2.62835778
C -2.63633913 -2.90501827 -2.62821488
C -3.51294598 -3.59065976 -3.50250103
H -1.75109055 -3.58866302 -1.74460125
H -0.88130838 -2.92029483 -0.87711257
C -0.88162585 -1.45831425 -0.87808105
H -1.75013735 -0.78918243 -1.74501744
H -0.00060874 -3.63108887 0.00172652
H 0.88017559 -2.92014107 0.88039669
C 0.88100433 -1.45816264 0.88066720
H -0.00013966 -0.74827117 0.00107519
H 1.74961738 -3.58840503 1.74829935
H 2.63503146 -2.90463121 2.63165492
C 2.63499478 -1.47124928 2.63105989
H 1.74971208 -0.78890240 1.74731880
H 3.51123315 -3.59019344 3.50640928
H 4.36075079 -2.89174895 4.35398313
C 4.36065204 -1.48165551 4.35330507
C 3.51097780 -0.78441715 3.50502503
C -5.03320558 -3.43555230 -5.01948809
C -3.51207269 -4.68369839 -3.50101416
C -5.03190244 -0.93828463 -5.01953200
C -3.50936731 0.30803600 -3.50098996
C -1.75664786 -4.68005159 -1.74945974
C -1.75572784 0.30192872 -1.75113041
C 1.75469251 -4.67979616 1.75389892
C 1.75567684 0.30221345 1.75287555
C 3.50985839 -4.68323080 3.50550975
C 5.03134898 -3.43491543 5.02351322
C 3.50925583 0.30852039 3.50286800
C 5.03111589 -0.93764693 5.02221792
C -4.35262750 1.48416794 4.36039981
C -4.35341783 2.89425834 4.35960886
C -3.50581678 3.59223285 3.50972962
C -2.63090006 2.90619986 2.63405558
C -2.63020343 1.47282034 2.63492559
C -3.50420389 0.78646817 3.51124438
C -1.74633378 0.78998081 1.75014787
C -0.87958723 1.45874225 0.88116052
H -0.87935502 2.92072728 0.87944728
H -1.74748106 3.58947011 1.74831347
H 0.00008527 0.74830909 0.00052136
H 0.87966359 1.45780303 -0.88096556
H 0.87871196 2.91978151 -0.88149571
H -0.00056980 3.63112176 -0.00163753
H 1.74686008 0.78813448 -1.74881314
H 2.63055221 1.47005572 -2.63446803
H 2.63044483 2.90343541 -2.63588025
H 1.74650554 3.58762451 -1.75136727
H 3.50507710 0.78280490 -3.50956777
H 4.35321419 1.47963340 -4.35971855
C 4.35316313 2.88972657 -4.36121558
C 3.50504110 3.58857051 -3.51257527
C -5.02157309 0.94052522 5.03112687
C -3.50197220 -0.30646925 3.51019523
C -5.02305027 3.43779359 5.02980700
C -3.50502982 4.68527028 3.50766878
C -1.75184000 -0.30112900 1.75679175
C -1.75321158 4.68086002 1.75262802
C 1.75288915 -0.30298134 -1.75380265
C 1.75137338 4.67900642 -1.75766699
C 3.50346832 -0.31013103 -3.50677907
C 5.02256931 0.93530500 -5.02948106
C 3.50355113 4.68160837 -3.51232836
C 5.02253072 3.43257250 -5.03223646
C -0.00061888 -5.13012795 0.00133455
C 0.86504300 -5.83921355 -0.86378101
C 0.85071377 -7.23925437 -0.84678250
C 0.00215018 -7.96216128 0.00157916
C -0.84390318 -7.24167108 0.85120670
C -0.86217672 -5.83960244 0.86687770
C 1.52549380 -7.78044084 -1.51701389
C -1.51209454 -7.78414687 1.52656571
H -0.00100708 5.13015302 -0.00281098
H -0.86479474 5.83816244 -0.86639952
H 0.86476243 5.84065660 0.86202187
H 0.84842593 7.24010203 0.84522049
H -0.00116418 7.96207625 -0.00378938
H -0.84844204 7.24082142 -0.85054544
H 1.52114068 7.78234520 1.51680087
H -1.52034097 7.78262959 -1.52264242
H 0.00453475 9.47233750 0.00385679
H -0.70448664 9.88284537 -0.73025452
H -0.27051253 9.86905300 0.99587252
H 1.00520724 9.87077833 -0.23418275
C -1.80058222 5.10656773 -1.80111928
C -2.39385178 5.81376719 -2.39898855
C -1.24762805 4.45363185 -2.49598546
C -2.49983316 4.45956670 -1.24662606
C 1.79945432 5.10741945 1.79647962
C 2.39927361 5.81349075 2.38911389
H 1.24462755 4.46113969 2.49612920
H 2.49227460 4.45330498 1.24237592
C -0.00913925 -9.47222855 -0.02013263
H -0.49950331 -9.88586838 0.87384538
H -0.55298559 -9.85392105 -0.90213704
H 1.01225269 -9.88251222 -0.06975067
C -1.79515034 -5.10879039 1.80499705
H -2.38703643 -5.81648284 2.40365127
H -1.24019811 -4.45667293 2.49903996
H -2.49567595 -4.46103530 1.25299847
C 1.80003883 -5.10522763 -1.79733936
H 2.39831725 -5.81085402 -2.39205533
H 1.24548005 -4.45670752 -2.49511192
H 2.49430791 -4.45326807 -1.24248675
END

BASIS spherical
* library cc-pvdz
END

DFT
mult 5
xc xcamb88 1.00 lyp 1.0 hfexch 1.00
cam 0.29 cam_alpha 0.0 cam_beta 1.0
direct
iterations 2000
grid nodisk
END


TDDFT
CIS
NROOTS 6
nosinglet
civecs
maxiter 500
END

task tddft energy

This however resulted in a ground state with spin <S2> = 15.0725, instead of a value around 6 for <S2> as I would like to have. The calculated excited states also have <S2> values around 15. A singlet calculation starting from the same multiplicity 5 configuration yields similar spin values, a result I cannot understand. I would appreciate if anyone has some input on that.

In general, is there a way to ask for excited states of a specific spin, e.g. 2? Thank you.

Best regards,

Antonis