Dear all,

I just have a question concerning the calculated difference density with ricc2. To get the spatial distributions, I am computing the densities for the ground and the first excited state with (scs) cc2. In my case, the calculations went smoothly and I have got the values on the grid. However, I am not confident with the interpretation of my results: in particularly, I am getting two files like cc2-xs1d-ur-1a-001.cao and cc2-xsdn-1a-001-total.cao. The difference densities calculated based on both types of files are very similar although they do not seem to be identical. My question is therefore the following: what is the precise difference between xs1d and xsdn types of densities and which of them (if any) contain the contributions from the correlation/doubles? Unfortunately, I could not find this in the manual. Essentially, I need this information to explain the difference in the performance of LR-CC2 with respect to TD-DFT on my system. Which densities (files) are more informative for this purpose?

Thank you in advance for your help!

Best regards,

Anton

P. S. I am using Turbomole 6.5