Non-performing of DSF calcuation at EOM-CCSD level

Questions
#1

I tried to compute singlet doubly excited state using DSF method at EOM-CCSD level of theory from a quintet state. It did not perform. Then I considered the example presented in QChem (Example 7.90) where the method is cisdt and I made a change with eom-ccsd. Again it didn’t work. Is this method implemented in QChem?

#2

EOM-2SF-CCSD is available in CCMAN but not CCMAN2. Refer to the Tables 7.1 and 7.2 in the manual (7.10.17 EOM-CC Job Control‣ 7.10 Coupled-Cluster Excited-State and Open-Shell Methods ‣ Chapter 7 Open-Shell and Excited-State Methods ‣ Q-Chem 6.2 User’s Manual). Use the following input:

$molecule
0 5
C
H 1 CH
H 1 CH 2 HCH

CH = 1.07
HCH = 111.0
$end

$rem
METHOD eom-cc(2,3)
BASIS 6-31G
DSF_STATES [0,2,2,0]
EOM_NGUESS_SINGLES 0
EOM_NGUESS_DOUBLES 2
CCMAN2 = false
$end

Alternatively, you can use the following $rem section:
$rem
correlation ccsd
eom_corr sdt
basis 6-31G
dsf_states [0,2,2,0]
eom_nguess_singles 0
eom_nguess_doubles 2
ccman2 false
$end

#3

Thanks, Kaushik. I have a small query: does this also apply to the Non-Hermitian complex basis functions (CBFs) approach?

#4

Not sure what you are implying here. If you are asking about CBF-EOM-CCSD, it is only implemented in CCMAN2. So, you cannot run it with 2SF method.

#5

Thanks for the note!