[molpro-user] Unclear problem in EOM-CCSD calculations: "small eigenvalue of S-eff matrix ... This can lead to convergence problems!"
evgeniy.gromov at pci.uni-heidelberg.de
Tue Jun 6 15:17:59 CEST 2017
I encountered some unclear problem when doing EOM-CCSD calculations
for an Ir complex. All steps till EOM went fine, but in EOM I get the
The smallest eigenvalue of S-eff matrix 0.8656157915E-13
This can lead to convergence problems!
and two of the five roots do not seem to have converged; there is
no "Converged" message for them after 50 iterations.
I wonder what this could be caused by? Could it be due to a very high
in energy (63.5 hartree) virtual orbital?
Dr. Evgeniy Gromov
Im Neuenheimer Feld 229
E-mail: evgeniy.gromov at pci.uni-heidelberg.de
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