#### 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.” 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. The default is to use all orbitals. 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.