Non-Iterative Triples Corrections to EOM-CCSD in 5.1 version

Dear Q-Chem Community,
I am trying to reproduce the examples 7.65-7.67 in the manual (vers. 5.1) with and without
the corrections fT/dT, the numerical values in the output are identical in both cases. I would expect some difference, or perhaps I am doing something wrong?

In general they should not be identical, e.g, for CH+, DZP basis set (one of the sample jobs provided with Q-Chem):

 dE(fT)=-0.0013798, E_CCSD(fT)=-38.0190500

 dE(dT)=-0.0017826, E_CCSD(dT)=-38.0194527

I don’t have a version 5.1 manual so I can’t see the examples to which you refer.

It is available here

pp. 385-386
I can’t attach the outputs, but all the values are identical for both eom-ccsd(ft) and eom-ccsd.

I have checked the version 6.0 and it’s working. This the example 7.107 from manual for 6.0 (p. 572).
This was a trial 6.0 version and we have only 5.1 license. Perhaps this problem can be somehow circumvented in the 5.1 version? Some additional keywords or some patch?

Hello @Leo137 ,

Could you try adding CCMAN2 = FASLE in $rem section and see if it works?


It doesn’t. Different jobs fail with different errors, e.g.

CCMAN error!NSDavidsonRight<T>::NSDavidsonRight() : invalid Nroots


*Nls: 441
lsGoal: 343
 Q-Chem fatal error occurred in module libint/aoloop_2BSet.C, line 672:
 AOI batch size too small.
 Please submit a crash report at 

Could you send the output file to I used 5.1.2 for the provided example and it finished with any issues. Note that if you are not using 5.1.2, you can upgrade to it without additional charge.

Yes, I’m using the version 5.1.2.
I have sent the outputs. The original example finishes without any issues, but does not contain the desired triples, see my first post.