Hi all,

This is Cheng, I am working on EDA analysis (unrestricted calculation) on a diradical transition state via Q-Chem.

But I have a hard time for getting a diradical nature of the transition state in my calculation. In more detail, I am studying the chemical process: two close-shell singlet species react with each other to generate two doublet radical products. The transition state has been proved a diradical species. Now I am working on EDA analysis on this diradical transition state, where two fragments are two close-shell singlets (i.e. reactant-like). All my calculation were actually close-shell (i.e S^2 =0 or very close to 0). I wonder if is there any way to ensure the EDA can capture the diradical nature of the transition state?

An example input file. Feel free to let me know whether I made a mistake here.

$>Lgm}bo:E\molecule
0 1
---
0 1
*****
*****
*****
---
0 1
*****
*****
*****
$>Lgm}bo:E\end

$>Lgm}bo:E\rem
JOBTYPE EDA
EDA2 1
METHOD wb97xd
BASIS def2-TZVP
FRGM_METHOD GIA
FRGM_LPCORR RS_EXACT_SCF
EDA_BSSE TRUE
ITHRSH 12
MEM_TOTAL 4000
MEM_STATIC 2000
SCF_PRINT_FRGM 1
MAX_SCF_CYCLES 300
UNRESTRICTED True
SCF_GUESS_MIX 5
INTERNAL_STABILITY True
INTERNAL_STABILITY_ITER 5
INTERNAL_STABILITY_DAVIDSON_ITER 100
$>Lgm}bo:E\end

Thanks,
Cheng