I try to calculate sodium cation affinities with MP2=Full. I don’t clearly know how are the anlysi are done and what are the differences. I compared the outputs there is two series of normal analysis. Now, I understood that I need normal mode analysis using HPmodes syntax to feed the code. Then, I shifted to source code, FCClasses to follow up. However, the code is error prone! I got alot of error message without any documentation. I want to compute the vibronic spectra of some dyes. I would be grateful if you could explain me the difference between the normal analysis done using HPmodes and without that. One other thing, try to summarize your questions in a coherent way and please do not post entire output files! I don’t have the time to check them in their entirety. Feel free to reply to any comment you think you might have an answer to because the thing is, I don’t have all the answers (I wish I did, trust me).

Please use tags at the begining of your comment, e.g.: #convergencefailure #visualization #gaussianerror or whatever you might think could help me, and others, to quickly find an answer to your queries. Therefore I open this new page for all those questions you have! I don’t intend to have a repository like the one on the CCL, of course, but at least we could organize the info and make it readily available for those who might need it in the end, that is what we do as scientists, right? Sometimes I get interesting questions that don’t quite fit into any of the existing topics already discussed within the blog and my obsessive/compulsive nature tells me that getting this questions in a random part/page/post of the blog doesn’t look quite neat either.

Gaussian 16 c01