*STEP CONTROL

Purpose:

User control of the NEO restricted step optimization.

.DAMPING FACTOR

Default = 1.0D0
READ (LUINP,*) BETA
Initial value of damping (BETA).

.DECREMENT FACTOR

Default = 0.67D0
READ (LUINP,*) STPRED
Decrement factor on trust radius

.GOOD RATIO

Default = 0.8D0
READ (LUINP,*) RATGOD
Threshold ratio for good second order agreement: the trust radius can be increased if ratio is better than RATGOD.

.INCREMENT FACTOR

Default = 1.2D0
READ (LUINP,*) STPINC
Increment factor on trust radius.

.MAX DAMPING

Default = 1.0D6
READ (LUINP,*) BETMAX
Maximum damping value.

.MAX STEP LENGTH

Default = 0.7D0
READ (LUINP,*) STPMAX
Maximum acceptable step length, trust radius will never be larger than STPMAX even if the ratio is good as defined by GOOD RATIO.

.MIN DAMPING

Default = 0.2D0
READ (LUINP,*) BETMIN
Minimum damping value

.MIN RATIO

Default = 0.4D0 for ground state, 0.6 for excited states
READ (LUINP,*) RATMIN
Threshold ratio for bad second order agreement: the trust radius is to be decreased if ratio is worse than RATMIN.

.NO EXTRA TERMINATION TESTS

Skip extra termination tests and converge micro iterations to threshold. Normally the micro iterations are terminated if the reduced NEO matrix has more negative eigenvalues than corresponding to the desired state, because then we are in a "superglobal" region and we just want to step as quickly as possible to the region where the Hessian (and NEO matrix) has the correct structure. Further convergence is usually wasted.

.REJECT THRESHOLD

Default = 0.25 for ground state, 0.4 for excited states
READ (LUINP,*) RATREJ
Threshold ratio for unacceptable second order agreement: the step must be rejected if ratio is worse than RATREJ.

.THQKVA

Default: 8.0 for MCSCF; 0.8 for QCSCF
READ (LUINP,*) THQKVA
Convergence factor for micro iterations in local (quadratic) region: THQKVA*(norm of gradient)**2

.THQLIN

Default: 0.2D0
READ (LUINP,*) THQLIN
Convergence factor for micro iterations in global (linear) region:
THQLIN*(norm of gradient)

.THQMIN

Default: 0.1D0
READ (LUINP,*) THQMIN
Convergence threshold for auxiliary roots in NEO MCSCF optimization.

.TIGHT STEP CONTROL

Tight step control also for ground state calculations (tight step control is always enforced for excited states)

.TOLERANCE

Default = 1.1D0
READ (LUINP,*) RTTOL
Acceptable tolerance in deviation of actual step from trust radius (the default value of 1.1 corresponds to a maximum of 10% deviation).

.TRUST RADIUS

Default = STPMAX=0.7D0 or, if restart, trust radius determined by previous iteration.
READ (LUINP,*) RTRUST
Initial trust radius.