MOLPRO

19 THE MCSCF PROGRAM MULTI 132
19.3.2 Defining the number of states in the present symmetry
STATE,nstate;
nstate is the number of states in the present symmetry. By default, all states are optimized with
weight 1 (see WEIGHT card).
19.3.3 Specifying weights in state-averaged calculations
WEIGHT,w(1),w(2),...,w(nstate);
w(i) is the weight for the state i in the present symmetry. By default, all weights are 1.0. See
also STATE card. If you want to optimize the second state of a particular state symmetry alone,
specify
STATE,2;WEIGHT,0,1;
Note, however, that this might lead to root-flipping problems.
19.3.4 Dynamical weighting
Dynamical weighting, as described in J. Chem. Phys. 120, 7281 (2004), can be activated using
DYNW,dynfac
The weights for each state are then computed as
w = 1/cosh(dyn f ac ∗ ∆E) 2 (45)
where ∆E is the energy difference (in Hartree) between the state under consideration and the
ground state. This is dynamically adjusted during the optimization process.
19.4 Defining the configuration space
By default, the program generates a complete configuration set (CAS) in the active space. The
full space may be restricted to a certain occupation pattern using the RESTRICT option. Alternatively,
configurations may be selected from the wavefunction of a previous calculation using
SELECT, or explicitly specified on CON cards. Note that this program only allows to select or
specify orbital configurations. For each orbital configuration, all spin couplings are always included.
Possible RESTRICT, SELECT and CON cards must immediately follow the WF card
which defines the corresponding state symmetry.
19.4.1 Occupation restrictions
RESTRICT,nmin,nmax,orb 1 ,orb 2 ,...orb n ;
This card can be used to restrict the occupation patterns. Only configurations containing between
nmin and nmax electrons in the specified orbitals orb 1 , orb 2 ,...,orb n are included in
the wavefunction. If nmin and nmax are negative, configurations with exactly abs(nmin) and
abs(nmax) electrons in the specified orbitals are deleted. This can be used, for instance, to omit
singly excited configurations. The orbitals are specified in the form number.sym, where number
is the number of the orbital in irrep sym. Several RESTRICT cards may follow each other.
RESTRICT only works if a CONFIG card is specified before the first WF card.