# 6.8. ¶

menuIt is a menu about Gaussian.

In order to use Gaussian you need to install Gaussian separately.

## 6.8.1. Configure¶

Set calculation conditions of Gaussian. To set up the calculations immediately after setting Run button, once to return to the main window please press OK button.

Behavior when clicking Run is see Run.

Return to the default state with Reset button. Save the current state as the default state with Save as Default button. Restore the default state to the factory condition with .

- Easy Setup
- Show the simple setting window.
- %nprocshared
- Specify the parallel number.
- Link0

- #nproc=n
- Specify the number of processors.
- #Chk=file
- Specify the checkpoint file.
- # Mem = n
- Specify the amount of dynamic memory in words. It is also possible to specify units of KB, MB, GB, KW, MB, GW. (Default: 6 MW)
- Comment
Write a comment.

- #
- Specify the beginning of the route section.
- #N
- Output is done at the standard level. (Default)
- #P
- Perform detailed output. The execution time at the start and end of each link, and the information on convergence of SCF are output.
- #T
- Specify a concise output that only outputs important information and results.
- Hamiltonian
Specify the Hamiltonian to use.

- Ltd.
- Perform Hartree-Fock calculation. Unless explicitly specified, RHF is used for singlet and UHF is used for higher multiplicity.
- rhf
- Restricted Hartree-Fock calculation is performed.
- uhf
- Unrestricted Hartree-Fock calculation is performed.
- am1
- We will perform semi-empirical calculations using AM1 Hamiltonian.
- pm3
- We perform semi-empirical calculation using PM3 Hamiltonian.
- pm3mm
- We perform semi-empirical calculations using PM3 Hamiltonian with molecular dynamics correction on HCON binding.
- b3lyp
- Compute the density functional method combining the Becke 3 functional with the LYP nonlocal correlation functional.
- ub3lyp
- Unrestricted version of b3lyp.
- mp2
- Following Hartree-Fock calculation, Moller-Plesset correlation energy correction up to the second order is performed.
- ump2
- It is an Unrestricted version of mp2.
- mp4
- Following Hartree-Fock calculation, Moller-Plesset correlation energy correction up to the fourth order is performed.
- ump4
- It is an Unrestricted version of mp4.
- cis
- Calculate the excited state using one-electron excitation CI.
- cisd
- Calculate the excited state using two electron excitation CI. (Synonymous with CI)
- indo
- We will perform semi empirical calculations using INDO Hamiltonian.
- ondo
- We will do semi-empirical calculations using CNDO Hamiltonian.
- gvb
- Perform general valence bond (GVB) calculation.
- oniom
- Perform ONIOM calculation.
- Basis
- Specify the set of basis functions.
- Pop
Control of molecular orbital output, electron density analysis, atomic charge distribution and so on.

- none
- It does not output molecular orbits and does not analyze electron density.
- minimal
- It outputs atomic charge and orbital energy.
- regular
- We output 5 occupied orbits and 5 virtual trajectories. Also output density matrix and Mulliken electron density analysis.
- full
- All occupied orbits and virtual trajectories are output. Also output density matrix and Mulliken electron density analysis.
- Calc. Type
Perform structure optimization calculation by EF (Eigen Vector Following) method.

- opt
- Perform structure optimization.
- opt=z-matrix
- Structure optimization is performed with internal coordinates.
- opt=modredundant
- redundant Add, delete, and modify the definition of internal coordinates (including search and binding information). An input section is required after the structure specification.
- opt=(ts,noeigentest,calcfc)
- Optimize for transition state. We do not test curvature. Calculate the force constant for the first time
- irc
- Track reaction path
- irc=(maxpoint=20, stepsize=20t, calcfc)
- It tracks the reaction path. Specify the number of points on the route and the step size. Calculate the force constant for the first time
- MaxCyc
- Sets the maximum number of optimization steps.
- Freq

- freq
- Calculate force constants and frequencies.
- freq=raman
- We calculate the Raman intensity in addition to the IR intensity.
- freq=vcd
- Calculate oscillating circular dichroism (VCD) intensity in addition to normal frequency analysis
- freq = noraman
- Hartree-Fock Raman intensity is not obtained by analytic frequency calculation.
- freq=nraman
- Calculate the polarizability derivative by numerically differentiating the analytical dipole derivative for the electric field.
- freq=nnraman
- Calculate the polarizability derivative by numerically differentiating the analytical polarizability on nuclear coordinates.
- Charge
- Specify the value of the charge.
- Multiplicity
- Specify multiplicity.
- for example,

- for example,
- Calculate excited state energy using time-dependent Hartree-Fock or DFT method
- td=(nstates=n)
- For the n states, we obtain the energy of the excited state using the time dependent calculation method. (Default 3)
- gfinput
- Outputs the basis function system in the same format as the input format.
- gfprint
- It outputs the basis function system in tabular form.
- nosymm
- Do not reorient the coordinates and perform all calculations in Z-matrix orientation.
- guess=read
- Read initial wave function from checkpoint file
- geom=check
- Fetch the molecule specification section from the checkpoint file.
- Others
- Fill in other keywords.

## 6.8.2. Import Keywords¶

Only keywords (calculation conditions) are read from the existing Gaussian input file.

## 6.8.3. Run¶

If Gaussian's input file is opened in the main window, use Gaussian to execute it. If it is not open, save the Gaussian input file and run Gaussian.

When saving the input file, output format of coordinates changes according to the selection of Coordinate Format choice (Z-Matrix or XYZ) and Z-Matrix / XYZ tab of Coordinate Viewer.

Gaussian's program path can be changed with:: menuselection: Tools –> Preferences –> Program Path.

Following file will be generated with execution. For example, the file/folder name when the input file is: file: water.gjf is shown together.

type Description log file`water.log`

Calculation log file. bat file`water.gjf.bat`

It is a batch file for running Gaussian. Working directory`water_gau_tmp\`

Working directory.The job is run through Winmostar Job Manager.

## 6.8.4. Open Log File (log/out)¶

Open the log file with a text editor.

## 6.8.5. Animation¶

### 6.8.5.1. Optimization¶

Creates and displays animation of structural optimization calculation from information of log file.

For the animation display operation method, see Animation window.

### 6.8.5.2. IRC/modred¶

Creates and displays animation of IRC calculation from information of log file.

For the animation display operation method, see Animation window.

## 6.8.6. Analyses¶

### 6.8.6.1. MO, UV-Vis, Charge & NMR¶

Information on molecular orbital, UV-Vis, charge, NMR from the information of the log file is acquired and displayed.

Information on the charge read can be displayed in Viewport by selecting

and so on.Refer to Energy Level Diagram window, MO Plot window, UV-Vis Spectrum window, NMR Window for how to operate the subwindow.

### 6.8.6.2. IR/Raman¶

Select the log file and display the vibration spectrum (IR or Raman spectrum).

Refer to IR Spectrum Window for how to operate the subwindow.

### 6.8.6.3. Archive¶

Read high-precision coordinates of the archive part of Gaussian's output.

### 6.8.6.4. RESP Charges¶

Calculate the point charge based on the RESP method from the esp file.

The esp file to be read must have been output from a calculation performed by selecting RESP/ESP in . Spin multiplicity is assumed to be 1. Internally, RESP charge is calculated using Antechamber.

To use this function, you need to use G09.C.01 or later version; if you use the version before G09.C.01, you need to change the IOP.

Warning

To use this function, CygwinWM setup is required.

## 6.8.7. FormChk¶

G09W, G03W Activate Formchk of utility, create formatted .fch file from .chk file and display it.

## 6.8.8. Import Fchk (Cubegen) File¶

G09W, G03W Start Cubegen of the utility, read the .fch file and create the Cube file. If you do not have Cubegen, use OpenCubegen from Winmostar.

For how to operate the subwindow, please refer to MO Plot window and the following.

- Property

- MO
- Molecular orbital
- Density
- Electron density
- ESP
- ESP
- Spin
- Spin density (α - β)
- Alpha
- α spin density
- Beta
- β spin density
- Current Density
- Current Density
- Shielding Density
- Shielding Density
- Type
- Specify the option of the Density keyword. (HF, MP 2, CI, QCI)
- Cube
- Output the Cube file.

## 6.8.9. Import Cube File¶

Read and display the Cube format file.

For GAMESS pun file, convert it to Cube file.

For how to operate the subwindow, please refer to MO Plot window and the following.

- cube Manipulation
Perform operations on cube files specified in File 1 and File 2.

- map
- Map the data in the lower column to the data in the upper column. (Example mapping ESP to Density)
- subtract
- We will cover the difference between the data of the two cube files.
- sub 2
- We will cover the difference between the squares of the data of two cube files.
- add
- We will cover the sum of two cube files.
- Cube
- The calculation result of the cube file targeted by Map is output and displayed.
- Cubegen
- Start Cubegen, read the fch file and create a Cube file. For details, see Import Fchk (Cubegen) File.

## 6.8.10. Paired Interacting Orbitals¶

Paired Interacting Orbitals Executes analysis. For details, see PIO analysis window.