%0 DATA
%A Brina, Brauer
%A Manoj K., Kesharwani
%A Jan, M. L. Martin
%D 2015
%T Some Observations
on Counterpoise Corrections for
Explicitly Correlated Calculations on Noncovalent Interactions
%U https://acs.figshare.com/articles/Some_Observations_on_Counterpoise_Corrections_for_Explicitly_Correlated_Calculations_on_Noncovalent_Interactions/2038986
%R 10.1021/ct500513b.s002
%2 https://ndownloader.figshare.com/files/3610302
%K ab initio methods
%K HF
%K BSSE
%K CCSD
%K MP
%K counterpoise
%K superposition error
%K Noncovalent InteractionsThe basis
%K basis sets
%K Explicitly Correlated Calculations
%X The
basis set convergence of explicitly correlated *ab initio* methods, when applied to noncovalent interactions, has been considered
in the presence (and absence) of Boys–Bernardi counterpoise
corrections, as well as using “half-counterpoise” (the
average of raw and counterpoise-corrected values) as recently advocated
in this journal [Burns, L. A.; Marshall, M. S.; Sherrill, C. D. *J. Chem. Theory Comput.* **2014**, *10*, 49–57]. Reference results were obtained using basis sets
so large that BSSE (basis set superposition error) can be shown to
be negligible. For the HF+CABS component, full counterpoise unequivocally
exhibits the fastest basis set convergence. However, at the MP2-F12
and CCSD(T*)-F12b levels, surprisingly good *uncorrected* results can be obtained with small basis sets like cc-pVDZ-F12,
owing to error compensation between basis set superposition error
(which overbinds) and intrinsic basis set insufficiency (which underbinds).
For intermediate sets like cc-pVTZ-F12, “half–half”
averages work best, while for large basis sets like cc-pVQZ-F12, full
counterpoise may be preferred but BSSE in uncorrected values is tolerably
small for most purposes. A composite scheme in which CCSD(T)–MP2
“high level corrections” obtained at the CCSD(T*)-F12b/cc-pVDZ-F12
level are combined with “half-counterpoise” MP2-F12/cc-pVTZ-F12
interaction energies yields surprisingly good performance for standard
benchmark sets like S22 and S66.