Hello everyone, I’m trying to calculate the rate of triplet triplet annihilation in molecule dimer, the refered paper is ‘First Principle Prediction of Intramolecular Singlet Fission and Triplet Triplet Annihilation Rates’ (doi:10.1021/acs.jctc.8b01185).Our group’s Q-chem version is 4.3.
I try to calculate the state energy of S0S1/S1S0(LE),T1T1(ME), and CT(charge transfer state) first.
1.The first question is: can I treat the dimer system just as monomer? If is different, how to change the key word?
2.I just treat the dimer system as monomer to calculate LE state, and the input file is like
$molecule
0 1
blablabla( pentacene dimer for example)
$end
$rem
jobtype sp
mem_total 80000
mem_static 10000
basis 6-31g*
correlation rasci
unrestricted false
ras_root 4
ras_act 4
ras_elec 4
ras_occ 266
ras_spin_mult 0
ras_natorb true
print_orbitals true
scf_final_print 1
$end
The error is “Odd number of electrons not allowed”.But the electron I set is even, so how can I fix the problem?
3.I try to use the FED(fragment excited difference)to calculate the energy transfer coupling, the input file is below.Because the system is dimer, I set STS_DONOR and STS_ACCEPTOR the same, but I get wrong data, so how to fix it？
if I set
$rem
METHOD CIS
BASIS 3-21G
CIS_N_ROOTS 20
CIS_SINGLETS true
CIS_TRIPLETS false
STS_FED true
STS_DONOR 1-164
STS_ACCEPTOR 1-164
$end