ccsd(t) vs. qcisd(t)
Is there any difference in chemical performance between the CCSD(T) and
QCISD(T) methods? All I've found are a few papers stating that ccsd is
"better" than qcisd, but the criteria used for judgment had little to
do with
real chemical problems.
QCI appears to lack (at least for now) a diagnostic analogous to Lee's T1 for
CC. Unfortunately, Gaussian-92 doesn't have T1 implemented.
Is there a publicly/commercially available program that will do CCSD(T)
calculations and with the following features (in order of decreasing
importance)?
1. T1 diagnostic
2. open-shell and closed-shell
3. faster than gaussian92
4. handles effective core potentials
5. direct methods
6. spin-orbit coupling (e.g., using effective potentials)
7. analytic derivatives
8. works on cray, convex, or RS/6000
9. easy to use
Please post any answers.
Thank you!
Karl
irikura' at \`enh.nist.gov