Multiwfn forum

I am trying to optimize the S1 excited state geometry (input: GS geometry coordinates) with the following input.

"! LibXC(B3LYP) D3BJ RIJCOSX def2-SVP TightSCF TightOPT DEFGRID3 OPT FREQ
! PrintBasis MiniPrint PrintMOs
! AIM xyzfile pdbfile

%pal
nprocs 32
end

%maxcore 20000

%TDDFT
NROOTS 5
IROOT 1
FOLLOWIROOT TRUE
TDA FALSE
END

*xyz 0 1"

I ended up 5 imaginary frequencies. Am I doing any mistake. Any guidance in this problem is appreciated.
Thank you

When I optimize the ground state (S₀) geometry in ORCA using the native B3LYP functional, the calculation runs without any problem.

However, when I attempt to optimize the first excited state (S₁), ORCA stops with an error and requests to use the LibXC implementation of B3LYP instead of the native one.

I would like to clarify the following points:

Are native B3LYP and LibXC(B3LYP) formally equivalent in ORCA, or are there meaningful differences in practice?

If LibXC(B3LYP) is required for excited-state optimizations (and for ESD calculations), is it recommended to also use LibXC(B3LYP) for the ground-state (S₀) optimization and frequency calculations to maintain methodological consistency?

Is it acceptable (from ORCA’s perspective and for publication-quality work) to optimize S₀ with native B3LYP and S₁ with LibXC(B3LYP), or should the same functional backend be used consistently for both states?

Any guidance on best practices for handling this situation would be greatly appreciated.

Dear Prof. Tian Lu,

I am using Multiwfn for post-processing of DFT/TD-DFT results (mainly from ORCA) and would like to kindly clarify one point. Could you please confirm whether Multiwfn can be used to calculate reorganization energy and Huang–Rhys factors (including mode-resolved contributions) for electronic transitions (e.g., S₁ ↔ S₀)?
If not, is there any possibility of implementing this option in near future?