Charge and multiplicity for non neutral fragments

1

Dear friends, I have a doubt.

I’m calculating the energy of a dimer, one of the fragments (fragment 1 in the example below) I know is not neutral.

molecule dimer {
 # here should go charge and multiplicity of fragment 1
fragment 1 coordinates
--
0 1
fragment 2 coordinates
}

If I don’t specify 0 1 (charge and multiplicity) for fragment 1 as in the example above, the input apparently runs. My question is: if I don’t specify 0 1 (charge and multiplicity) for fragment 1, does the psi4 deduce whether it is an anion or cation if I don’t specify it in the input (i.e., leave blank as in the example)?

For charge, the options are just -1 for anions, 0 for neutral and +1 for cations or can I have values ​​such as -2, +2… depending on the formal charge of the fragment ? Is there any way to determine this value easily?

I couldn’t find anything like this explicit in the manual.

Thanks in advance.

Best,

2

The default is charge 0 and multiplicity 1. There is no logic to try to deduce the correct charge and spin state; this is the responsibility of the user!