Key to control the automatic geometry optimization.
GeoOpt
Iterations n
Converge {Grad=tolgrad} {E=tolE} {Step=tolStep}
TrustRadius radius
UseVariableTrustRadius var
InitialHessian filename | UnitMatrix| Swart
RestartSCF {true | false}
GDIIS {true | false}
End
Iterations: the maximum number of cycles: default 50
Converge {Grad=tolgrad} {E=tolE} {Step=tolStep}: various criteria to determine the convergence can be specified on line. Here tolGrad is the maximum gradient allowed (default=1.0e-2 Hartree per Angstrom), tolE is the maximum energy change allowed (default 1.0e-3 Hartree), tolStep is the maximum step size (default 3e-2 bohr)
TrustRadius: The step sizes taken by the optimizer will be limited to this value (default = 0.2 bohr). If the proposed step is larger it will be scaled back.
UseVariableTrustRadius: Automatic adjustment of the trust radius based on the observed energy changes. Default: false.
InitialHessian: The initial hessian is read from a "RUNKF" file filename of a previous frequency calculation. By default the unit Hessian will be used. Another option is to use the empirical force field derived Swart Hessian.
RestartSCF: During the optimization try to restart the SCF from the previous geometry step. (default = true)
GDIIS: Use the GDIIS convergence accelerator (default = false)
Note that a (failed) geometry optimization can be continued with the Restart key by specifying as option GeometryOptimization.
