Hi Alex,
I have also noticed this behavior. If you have a sequence of excitation 1a', 2a', 1a", 3a',
change the symmetry to C1 and calculate the first 3 excitations in a, the 3a might not
correspond to 1a", but to 3a'.
As far as I understand it, this is due to the fact, that the solution vectors generated
initially before the CCS preoptimization, do not cover this excitation.
You can avoid it, if you choose to create more start vectors, i.e. in this case
$excitations
irrep=a nexc= 3 nstart= 4
Cheers,
Arnim