### two-photon transition strength/(S_{0f}

Posted:

**14 Oct 2015, 09:48**Dear all,

I have question regarding to the evaluation of two-photon transition

strength using CCSD method in Dalton package.

As you can see in the attachment, I calculated the two-photon

transition matrix elements (S_{0f}) for the fenchon molecule. As you

can see the signs of all S_{0f} are positive. I did the similar calculation

using DFT, but I obtained some values with positive and negative signs

for the two-photon transition tensor matrix. Now my question is: Are the

calculated two-photon transition matrix elements (S_{0f}) in CCSD

calculation presented by their absolute values in the output file

(see attachment)? and if yes, is there any way to find out the signs

of the two-photon transition matrix elements (S_{0f}) in CCSD

calculation?

Thank your very much in advance for your help

Best regards,

Behnam

I have question regarding to the evaluation of two-photon transition

strength using CCSD method in Dalton package.

As you can see in the attachment, I calculated the two-photon

transition matrix elements (S_{0f}) for the fenchon molecule. As you

can see the signs of all S_{0f} are positive. I did the similar calculation

using DFT, but I obtained some values with positive and negative signs

for the two-photon transition tensor matrix. Now my question is: Are the

calculated two-photon transition matrix elements (S_{0f}) in CCSD

calculation presented by their absolute values in the output file

(see attachment)? and if yes, is there any way to find out the signs

of the two-photon transition matrix elements (S_{0f}) in CCSD

calculation?

Thank your very much in advance for your help

Best regards,

Behnam