Hi everyone,
I performed EOM-CCSD QM/MM calculation for H2O molecules as a test case. My question is how to get the excitation energy? NWChem does not print it explicitly.
The following is the input file:
start e4h2o
memory total 4500 Mb
charge -1
basis spherical
* library 6-31++g**
end
scf
thresh 1.0e-10
tol2e 1.0e-10
doublet
rohf
end
md
system e4h2o_opt
cutoff 1.0 qmmm 1.0
noshake solute
end
qmmm
mm_charges expand all
end
tce
freeze atomic core
ccsd
tilesize 8
attilesize 60
2eorb
2emet 14
diis 5
thresh 1.0d-5
nroots 2
eomsol 2
idiskx 1
end
task tce qmmm energy
The following is part of the output file, if you interested in the file, I can email it to you.
EOMCCSD root nr. 1
Singles contributions
22a (alpha) --- 21a (alpha) 0.8957902018
25a (alpha) --- 21a (alpha) -0.1010208625
26a (alpha) --- 21a (alpha) 0.1495866218
27a (alpha) --- 21a (alpha) 0.2654077772
28a (alpha) --- 21a (alpha) -0.1891541423
34a (alpha) --- 21a (alpha) 0.1191698732
Doubles contributions
EOMCCSD root nr. 2
Singles contributions
22a (alpha) --- 21a (alpha) 0.1078353808
23a (alpha) --- 21a (alpha) 0.8192252691
24a (alpha) --- 21a (alpha) -0.2875936030
26a (alpha) --- 21a (alpha) -0.2268543499
27a (alpha) --- 21a (alpha) -0.3199715289
29a (alpha) --- 21a (alpha) 0.1373032935
Doubles contributions
Parallel integral file used 436 records with 0 large values
Bq nuclear interaction energy = 6.89703372905328
QM/MM Energy
quantum energy -305.169313270 (-.801222E+06 kjoule/mol)
quantum energy adjusted -305.169313270 (-.801222E+06 kjoule/mol)
quantum energy internal -312.066346999 (-.819330E+06 kjoule/mol)
Bq-nuclear energy 6.897033729 (0.181082E+05 kjoule/mol)
Bq-electron energy 0.000000000 (0.000000E+00 kjoule/mol)
classical energy -4.752909506 (-.124788E+05 kjoule/mol)
total qmmm energy -309.922222776 (-.813701E+06 kjoule/mol)
Thanks in advance.