Hi there,
I am using CIS to calculate the electronic transition energy and transition dipole moment. In the output there are lines like (it is for h2o):
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Root 1 singlet b2 0.292135972 a.u. 7.9494 eV
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Transition Moments X 0.00000 Y -0.26644 Z -0.00000
Transition Moments XX 0.00000 XY 0.00000 XZ -0.00000
Transition Moments YY 0.00000 YZ 0.06726 ZZ 0.00000
Dipole Oscillator Strength 0.01383
Occ. 5 b2 --- Virt. 6 a1 -1.00006 X
I am wondering if I can trust the sign/direction of the transition moment in the output file (-0.26644 in this example). My impression (which might be wrong) is that the wave function has an arbitrary phase so that only the magnitude of the transition dipole moment is reliable. If my impression is correct, how can I determine the sign/direction of the transition dipole moment from the output information (presumably the transition dipole moment has a unique direction.)?
Thanks a lot!
Best regards,
Liang
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