Avogadro/C4/File-Extensions/English
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Slide Number 1
Title Slide |
Welcome to this tutorial on File Extensions. |
Slide Number 2
Learning Objectives |
In this tutorial, we will learn to,
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Slide Number 3
Learning Objectives |
* And view Molecular orbitals and
calculated IR spectrum using output files generated from:
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Slide Number 4
System Requirement |
Here I am using
Ubuntu Linux OS version. 14.04. Avogadro version 1.1.1. |
Slide Number 5
Pre-requisites |
To follow this tutorial you should be familiar with,
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Cursor on the slide. | Please download and save them in a folder on desktop. |
Open Avogadro window using dash home. | Here I have opened the Avogadro window. |
Click on build menu.
Scroll down to Insert then fragment. Double click on aromatics folder and select benzene.cml file. |
Load a benzene molecule from Build menu using Insert fragment library. |
Click on auto-optimization tool.
In the auto-optimization settings, change force-field to MMFF94. Click on start. |
Optimize the geometry using Auto-optimization tool from the tool bar. |
Click on the Extensions menu and scroll down. | Click on the Extensions menu.
Using Avogadro we can prepare input files for popular quantum codes such as: GAMESS Gaussian MOLPRO MOPAC Q-CHEM etc. |
Click on Gaussian.
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Click on Gaussian option.
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Cursor on Gaussian input box. | Let me demonstrate how to generate input file for Gaussian program.
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Cursor on Gaussian input box. | Avogadro by itself cannot calculate molecular orbitals.
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Cursor on Gaussian input box.
Type the title as Benzene-MO. |
In Gaussian input dialog box , type the title as Benzene hyphen MO. |
Choose Frequencies from the Calculation drop-down.
Set 1 for the processors. Theory as B3LYP. Basis as 6-31G(d). Charge zero. Multiplicity 1. Output as Standard. Format as cartesian Check the checkpoint check box. |
Choose Frequencies from the Calculation drop down.
Processors as 1. Theory as B3LYP. 6-31G(d) as Basis set. Charge zero. Multiplicity 1. Output as Standard. Format as cartesian Check the checkpoint check box. |
Cursor on the text box. | You can see the preview of the input file at the bottom of the dialog box.
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Click on Generate button.
A Save input Deck dialog box opens. |
Click on Generate button.
A Save input Deck dialog box opens.
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Type the file name as Benzene, choose the location as Desktop.
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Type the file name as Benzene.
Choose the location as Desktop.
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Cursor on the file Benzene.com on the desktop.
Open Benzene.com. |
The file will be saved as Benzene.com on the desktop.
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Slide Number 6
Gaussian Software |
About Gaussian software.
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Click on New from the tool bar.
In the draw settings select oxygen as element |
Back to Avogadro window.
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Click on extensions menu, select GAMESS Input generator from the submenu. | Click on Extensions menu.
Select GAMESS, Input generator from the sub-menu. |
Cursor on the GAMESS-Input dialog box.
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A GAMESS input dialog box opens.
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Type,
In gas phase, singlet. Charge as Neutral. |
Under Basic Setup,
we will select Equilibrium Geometry under Calculate field.
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Click on advanced set up. | Click on Advanced Setup to add some more parameters to control the optimization. |
Click on Basis. | Click on Basis if you want to change the set of functions. |
Click on Data.
Type the Title as Benzene MO. Type the Point Group as CnV. |
Click on Data.
Type the Title as water-MO. Change the Point Group to CnV. Order of Principal Axis to 2. |
Click on Generate.
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For now we will keep the default parameters as such.
Click on Generate.
By default, the file extension is dot inp.
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Choose the file location as Desktop.
Click on Save button. |
Choose the file location as Desktop.
Click on Save button. |
Cursor on Desktop. | The GAMESS input file is saved as Water.inp on the Desktop. |
Slide Number 7
About GAMESS |
About GAMESS
GAMESS stands for: General Atomic and Molecular Electronic Structure System. (GAMESS)It is a general ab initio quantum chemistry package. |
Slide Number 8
About GAMESS |
It is available at no cost to both academic and industrial users.
Information about installation and download is given at the following link. |
Cursor on the panel. | Now we have generated input files for GAMESS and Gaussian programmes.
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Slide Number 9
Note for the viewers |
Viewers please note:
Gaussian is a commercial software. Hence I will not be able to show the interface to load the input file. |
Slide Number 10
Note for the viewers |
As mentioned earlier GAMESS is free software.
Those interested can download GAMESS software from the given link. And load the input file to generate the output file. |
Cursor on the panel. | I have some Gaussian and GAMESS output files on the desktop.
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Clck on open icon in the tool bar. | Open a new Avogadro window.
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Navigate to desktop files.
Select Benzene.log |
Navigate to the file location.
Select Benzene.log |
Cursor on the panel. | The file opens, we can see the structure of benzene on the panel. |
Benzene.log was generated using Gaussian.
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Cursor on the panel. | Sometimes the log file may not show orbital information.
In such case open the .fchk file provided in the codefiles. |
Click on the orbital from the list.
Observe the panel. |
To view the orbitals, click on the orbital name from the list. |
Click on the spanner symbol next to surfaces option in the display types. | If you want to change the display of orbitals....
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Cursor on the Surface Setting dialog box.
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In the Surface Setting dialog box.
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Click on Render tab.
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There are three options in the Render drop-down, fill, lines and points.
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Click on the Color tabs next to positive and negative option.
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There is also an option to change the color of the lobes.
Click on the Color tabs next to positive and negative option. A Select Color dialog box opens. Click on any color to select. Click on OK button. Observe the panel, the colors of the orbitals are now changed. Close the dialog box. |
Uncheck the Surfaces option in the Display Types dialog box. | To remove the orbitals from the structure;
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Click on vibrations tab. | Click on Vibrations tab to view the vibrational frequencies. |
Cursor on Vibration window.
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In the Vibration window, click on any frequency from the list.
Click on Start Animation button present at the bottom of the window. Observe the panel. The stretching of C-C and C-H bonds are animated. |
Click on Show Spectra.
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We can also view the IR spectrum for the structure.
Click on Show Spectra. A Spectra Visualization window opens. It shows the calculated IR spectrum of Benzene. |
Navigate to the file on desktop using Open option in the tool bar.
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Open a new window.
Open the log file created for water molecule using GAMESS programme. |
Cursor on the panel. | The log file opens with a structure of water and Molecular orbital information. |
Click on the name of the orbital from the list. | Click on the name of the orbital from the list.
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Slide Number 11
Summary |
Let's summarize
In this tutorial we have learnt to, Prepare the input files for computational chemistry programmes such as:
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Slide Number 12
Summary |
View Molecular orbitals for benzene and water molecules.
View calculated IR spectrum for molecules using log files generated from Gaussian. |
Slide Number 13
Assignment |
For Assignment,
Open the log file for benzene molecule from the code files provided. Display any Molecular Orbital from the list. Change the display and color of the lobes. Save the image in JPEG format. |
Slide Number 14
Acknowledgement |
* This video summarizes the Spoken Tutorial project
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Slide Number 15 | * We conduct workshops using Spoken Tutorials and give certificates.
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Slide number 16 | The Spoken Tutorial Project is funded by NMEICT, MHRD Government of India. |
Slide number 16 | This is Snehalatha from IIT Bombay signing off.
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