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** Next:** 19.6 Program control using
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** Previous:** 19.4 Print options
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##

19.5 Convergence thresholds

As for the print options, there are global and local thresholds, specified using
the `gthresh` and `thresh` directives, respectively. Here we only mention some
useful global thresholds (default values are shown).

gthresh,energy=1.d-6 !convergence threshold for energy.
!This affects all iterative methods
gthresh,orbital=1.d-5 !convergence threshold for orbitals.
!This affects scf only
gthresh,step=1.d-3 !convergence threshold for orbital rotations
!This affects mcscf only
gthresh,gradient=1.d-2 !convergence threshold for gradient with respect to
!orbital rotations. This affects mcscf only
gthresh,civec=1.d-5 !convergence threshold for ci-coefficients in ci and ccsd.
gthresh,optgrad=3.d-4 !threshold for gradient in geometry optimizations
gthresh,optenerg=1.d-6 !threshold for energy in geometry optimizations
gthresh,twoint=1.d-11 !Threshold for neglect of small 2-electron integrals
gthresh,compress=1.d-11 !Accuracy of integral compression (depends on twoint)
gthresh,printci=0.05 !print all ci-coefficients larger than 0.05
gthresh,punchci=0.05 !write all ci-coefficients larger than 0.05 to the punch file

Note that the energy threshold also affects the defaults for some
other thresholds such as `orbital`, `step`, and
`civec`, and therefore it is normally sufficient to lower the energy threshold
if high accuracy is needed.

Any number of thresholds can be specified on a single `gthresh` directive, e.g.,

`gthresh,energy=1.d-8,printci=0.03`

molpro@molpro.net 2018-06-21