Error in EOM-CC calculation

1

Dear friends,

I ran to some errors while trying EOM-CC calculations.

  1. for error: ** Lambda not converged to 1.0e-07 **
    what input should I include to make it working?

  2. for error: PSIO_ERROR: Can’t find TOC Entry EOM CC2 Energy for root 1 4
    what should I do with it? I checked the output and it seems all the roots I needed were converged, including root 1 4.

  3. my iput is something like this:

set {
basis aug-cc-pVDZ
freeze_core true
roots_per_irrep [5, 5]
}

property(‘eom-cc2’, properties=[‘oscillator_strength’])

My molecule is quite small (8 atoms). If I need a lot of roots (around 200 roots, which can be done easily with TDDFT), is it feasible with EOM-CC2? if yes, what input are needed to control the convergence?

Thank you very much!

Best regards,
Michael

2

The default convergence of the CCLAMBDA code for transition properties, such as oscillator strengths is too tight, and I need to adjust it. In the meantime, you should be able to get a significant number of states – but probably not 200 – by adding the following to your input file:

set cclambda {
  r_convergence 1e-3
}
set cceom {
  r_convergence 1e-3
  e_convergence 1e-5
}

-TDC

1 Like