Zindo Keyword
Last Update: 06/29/2001

This method keyword requests an excited state energy calculation using the ZINDO-1 method. Note that ZINDO calculations must not specify a basis set keyword.

By default, a ZINDO calculation is performed using the ten highest occupied orbitals and the ten lowest virtual orbitals. Use the Window option to define a different orbital set.

ZINDO jobs will also usually include the Density keyword; without options, this keyword causes the population analysis to use the current density rather than its default of the Hartree-Fock density.

The output from a ZINDO calculation is very similar to that of a CIS calculation as described previously.

Singlets

Solve only for singlet excited states. Only effective for closed-shell systems, for which it is the default.

Triplets

Solve only for triplet excited states. Only effective for closed-shell systems. 50-50 Solve for half triplet and half singlet states. Only effective for closed-shell systems.

Root=N

Specifies the "state of interest," for which the generalized density is to be computed. The default is the first excited state (N=1).

NStates=M

Solve for M states (the default is 3). If 50-50 is requested, NStates gives the number of each type of state for which to solve (i.e., the default is 3 singlets and 3 triplets).

Add=N

Read converged states off the checkpoint file and solve for an additional N states.

Window=(m[,n])

The two values specify the starting and ending orbitals to be used. A value of zero indicates the first or last orbital, depending on where it is used. If the value for the first orbital is negative (-m), then the highest m orbitals are retained; the value for the last orbital is negative (-n), then the highest n orbitals are frozen. If m is positive and n is omitted, n defaults to 0. If m is negative and n is omitted, then the highest |m| occupied and lowest |m| virtual orbitals are retained. (See the discussion of the MP2 keyword for examples.)

Energies only.

CIS, TD, Density.