symmetry use in TDDFT

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Hi All,
I am trying to calculate first 12 roots of b3 irrep in D2 group using "symmetry" and "targetsym" keywords in the tddft block. Any combination of these two keywords, as well as using them separately, always produces roots in all four representations of this group. What am I missing? Thanks in advance!
Maria
Here is my input:
echo
title "ch4-Tdsym test"
geometry units angstroms print
H -0.629312 0.629312 0.629312
C 0.000000 0.000000 0.000000
H 0.629312 -0.629312 0.629312
H 0.629312 0.629312 -0.629312
H -0.629312 -0.629312 -0.629312
symmetry group d2
end
basis spherical noprint
  • library aug-cc-pvdz
end
dft
xc xcampbe96 1.0 cpbe96 1.0 HFexch 1.0
cam 0.30 cam_alpha 0.25 cam_beta 0.75
direct
iterations 100
end
tddft
symmetry b3
targetsym b3
nroots 12
notriplet
end
task tddft energy

  • Niri Forum:Admin, Forum:Mod, NWChemDeveloper, bureaucrat, sysop
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Threads 4
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Hi Maria,

This is indeed the case. Only excitations from states that have the specified irrep are considered. However, this is a very high symmetry case and there are many degeneracies and we print out the lowest N excited states. You can see this if you comment out the symmetry and targetsym in the tddft block.

I'll look into this to see if the output can be further clarified.

Best regards,
-Niri
niri.govind@pnnl.gov


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