# Geometry Optimization#

It is possible to perform geometry optimization calculation of the
target molecule using Berny algorithm before the VQE and chemical
property calculations. The algorithm chosen at *solver* is used for
energy evaluation while geometry optimization is performed.

## Options#

target_state: Specifies the state index of which the eigenenergy is minimized during geometry optimization

excited_state_type: If

`target_state`

is set to equal or larger than 1, the method for calculating electronically excited states can be selected from the following:*STATE_AVERAGED*: the default, where each electronic excited state is equally weighted.*STATE_SPECIFIC*

weights: The weight of state-average can be specified as a list. If not given, equal weighting is applied.

The following fields specify convergence criteria:

gradientmax: the maximum force component (in a.u.)

gradientrms: the root-mean square force (in a.u.)

stepmax: the maximum step component (in Bohr)

steprms: the root-mean-square step (in Bohr)

maxsteps: the maximum number of steps

### Notes#

Geometry optimization is not supported when:

the system with spatially periodic boundary condition (

*Target Periodic System*) is subject to calculationdensity fitting approximation is used

`MCVQE`

is chosen for*Solver*

### Input example#

```
"geometry_optimization": {
"target_state": 0,
"gradientmax": 1e-4,
"gradientrms": 1e-4,
"stepmax": 2e-2,
"steprms": 1.5e-2,
"maxsteps": 1000,
}
```