630. Making MO figures in gabedit using fchk files from gaussian on Windows XP

630. Making MO figures in gabedit using fchk files from gaussian on Windows XP

August 02, 2016
The goal is to show how to make pretty figures of MOs from Gaussian computations using GabEdit.

This is a write-up for a colleague whom is using Windows. The GabEdit bits work pretty much the same way on linux, although the povray stuff is a lot easier (in my opinion anyway) on that OS.

Anyway, Windows it is.

A. Optional: Install Gaussian (G09W)
If you have G09W you can install it. To use the formchk utility, add the location of your gaussian installation to path.

Do this by right-clicking on My Computer, select the Advanced tab, click on Environment Variables, and then click on the Path entry under System Variables. Click Edit, and add
;c:\g09w
if that's the correct path for you. The ";" is just to separate your entry from the previous one. If you need to add another entry afterwards (e.g. for povray), put a ";" after c:\g09w



Either way it's optional, as you will likely have access to formchk on the same computer/system that you ran your job on and can do the chk -> fchk conversion there.

Also, using formchk on a windows computer on a .chk file from a linux computer might not work (which was my case)

An alternative is to set up a smallish linux VM: https://verahill.blogspot.com.au/2016/08/631-small-linux-installation-in.html

B. Optional: Add option to open terminal using mouse
Following this: https://stackoverflow.com/questions/378319/windows-explorer-command-prompt-here/379804

Create a plain text file called context.reg



Edit it and put the following in it:

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\cmd]
@="Open Command Prompt Here"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\cmd\command]@="cmd.exe /k pushd %L"

Like so...
Run it (i.e. double-click):
Yes!
You will now have an "Open Command Prompt Here" option when right-clicking on a folder in the file explorer.
Open terminal here
Why do this? Because it makes it easier to run either formchk or povray in the directory where you have your files.

C. Install gabedit
Got to https://sites.google.com/site/allouchear/Home/gabedit/download and get "The Gabedit installer for Windows (OpenGL)"

Run. It's that easy.

When running gabedit for the first time you may be asked lots of questions. You can probably just accept all the defaults. We'll change some of them below.
D. Install povray
Download http://www.povray.org/redirect/www.povray.org/ftp/pub/povray/Official/povwin-3.7-agpl3-setup.exe and also accept to install the editor dlls at the end of the installation.
Download povray
Once that's done, add povray to path. Go to My Computer, right-click, click on the Advanced tab, select Environment Variables, click on path under System Variables and then Edit. Add
;C:\Program Files\POV-Ray\v3.7\bin

Like So

Let's get going!
1. Optional: Convert chk to fchk using formchk
Didn't work for me, but you can always try (I convert the files under linux)

Either way, you must have the fchk file before going to gabedit



2. Open fchk file in gabedit
You need to do a bit of setting up:

Set path and command for povray






To look at the fchk file:
a) Go to Display
Display Geometry/Orbitals/Density/Vibration


b) unset dipole (because otherwise you'll have an annoying arrow in your figure)
Untick dipole

c) Set desired atom colours.
In particular, I change N from dark blue to light blue so that it doesn't interfere with the orbital colours.
Atom colour

d) Set backgrounds (povray and screen) to white
Povray background

Window background


e) load fchk file
Go to Orbitals/Gaussian fchk


Open your fchk file


f) Set ball/stick parameters
Set Ball and Stick parameters
Apply

g) select level/MO
Note that you get the alpha OR beta orbitals. For a spin restricted system these are the same (apart from signage)

You should edit number of points. 65 is the default. 80 is slow but manageable. 90 is pushing it. Higher = smoother.

Computing...

"Get Isovalue" almost never works properly. Try 0.04-0.06.

Et voilá!
To select a different MO, go back to orbitals and click on Selection.
Selection

h) Edit surfaces
You can change colours and transparency
Transparency is an option

Adjust the transparency/opacity here
i) Export pov
To make a publication-worthy figure, export as pov
Export as Povray
Clicking 'Run' occasionally leads to crash, so it's safer to click on save. Make sure that the background in white.

Edit the command to +A0.01 instead of +A0.3 for less 'pixelated' figure on zooming in. Takes a bit longer to render though. The H/W values depend on your window shape.

Select save, not Run

3. Render povray
You now have a pov file (example.pov). The most straight-forward way to render it is to open the command prompt (terminal) in the same folder and run
pvengine +A0.01 +H604 +W620 example.pov
Rendering

assuming that the H/W values are the ones listed (or multiples of them) when you saved the pov file (it'll be listed in example.bat in the same folder).

And it looks like this:
A basic POV-Ray generated png


You can also run the .bat file associated with the pov file, but note that you'll have to put paths in "":
You need ""s
You can also render in the povray editor (open the povray with the editor):
Povray editor


Render Settings

The issue becomes the default H/W (resolution) values. Override using command line options: +HXXX +WYYY
You may have to associate .pov files with pvengine manually:

Edit -- but you'll be told that there's no program


Select a program to open



pvengine


Always use the selected program

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