34.5 Examples

Example 1:
```***,The five lowest singlet excited states of water molecule
memory,64,m
gdirect
symmetry,nosym;orient,noorient
geometry={
o ,,  0.000,  0.000,  0.119
h1,,  1.423,  0.000, -0.947
h2,, -1.423,  0.000, -0.947 }
basis={
default,vdz
set,mp2fit
default,vdz/mp2fit
set,jkfit
default,vdz/jkfit }
hf
{lt-df-lcc2                     !ground state CC2
eom,-6.1                        !five lowest states
eomprint,popul=-1,loceom=-1 }   !minimize the output
```
The excitation energies (in eV) stand after the calculation in array OMEGAF_S for singlet states and in OMEGAF_T for triplet states.

Example 2:

```***,The five lowest triplet excited states and properties
memory,64,m
gdirect
symmetry,nosym;orient,noorient
geometry={
o ,,  0.000,  0.000,  0.119
h1,,  1.423,  0.000, -0.947
h2,, -1.423,  0.000, -0.947 }
basis={
default,vdz
set,mp2fit
default,vdz/mp2fit
set,jkfit
default,vdz/jkfit }
hf
{lt-df-lcc2                     !ground state CC2
!five lowest triplet states, dipole moments for four lowest, density saved:
eom,-6.1,triplet=1,singlet=0,propes=-5.1,densave=5000.2
eomprint,popul=-1,loceom=-1 }   !minimize the output
!ground state density, file h2o0_density.cube:
{cube,h2o0,,80,80,80
density,5000.2,cc2 }
!difference excited state density, file h2o1_density.cube:
{cube,h2o1,,80,80,80
density,5000.2,diff,state=2.1 }
```

In order to set up an input for a geometry optimization of an excited state we recommend to use the input examples furan_opt_ltdflcc2lr.com (for local CC2) and furan_opt_ltdflucc2lr.com (for local ADC(2) aka TD-LUCC[2]-H) as templates. Provided that second-order methods like CC2 or ADC(2) are appropriate for the state to be optimized, it is recommended to use local ADC(2) rather than local CC2, since the former is considerably faster. Even if a local CC2 optimized geometry of an excited state is required, it is wise to preoptimize with local ADC(2). For a comparison of the performance of these two methods in geometry optimizations we refer to Ref. [8].

molpro@molpro.net 2019-05-25