Aritra Roy

Pondicherry University · Department of Chemistry

I was trying to optimize an organoaluminium compound using the PBE0-D3(BJ)/def2-SVP level of theory. I have not used this theory before for my work. But after reading the Gaussian documentation and googling, I came up with the input like below -

But Gaussian is throwing a syntax error in the basis set input. Can anyone help me with this issue?

The gaussian output message is attached below.

I have a metallic structure. I have run geometry optimization first with 550eV energy cutoff, 0.02 k-mesh, and ultrasoft PP. Then when I tried to run a Phonon calculation with IR frequencies calculation it always failed. I then did a phonon calculation specifically for metal (clicking the checkbox in the CASTEP Calculation setup tab), and it was successful.

But there were large -Ve frequencies for acoustic bands (~9.8 THz). So, I wanted to check the IR frequencies corresponding to the -Ve frequencies. But if I select both metal and IR calculation (as well as polarisability), an error message pops up like the attached screenshot. Now, I performed an IR frequency calculation with the resultant phonon structure, but there was no -Ve frequency.

I have just started using ORCA and was following a YouTube tutorial series by Dr. S. Kishor => https://www.youtube.com/playlist?list=PLJIwRG-f5Gjd95jUG4cGjfSxs2gQfQAza

I'm using ORCA 5.0.3 on windows 10 with an i5 9400 processor and 500 GB A2000 Kingston RAM. In the 16th video of the series, I was introduced to IR frequencies calculation with geometry optimization with the following input -

# avogadro generated ORCA input file

# Basic Mode

# GeomOpt + Freq for Acetone

! RHF OPT FREQ 6-311++G**

* xyz 0 1

C -3.50986 2.85550 -0.14979

C -2.02053 3.03306 -0.02862

H -3.77767 1.82632 0.10157

H -3.82355 3.06176 -1.17685

H -4.01762 3.55239 0.52151

C -1.41776 2.78670 1.32795

H -1.61034 1.75505 1.63245

H -1.85017 3.48112 2.05247

H -0.33688 2.94710 1.28593

O -1.32971 3.36340 -0.99127

*

Now, when I'm opening the output file (.out) using Avogadro 1.2.0, the molecule was loading, but the frequencies were not loading. I checked the output file, and they were there but were not coming in Avogadro (should render automatically while opening the output file). I opened the Vibration toolbar from the settings of Avogadro to find they were not loaded. Can anyone help me how to view the IR frequencies generated from ORCA in Avogadro or other software?

N.B. - I found a discussion in the ORCA forum about OfakeG which can convert the ORCA output file into a Gaussian output file and I used that to covert as I have institutional access to Gaussian and GaussView (https://orcaforum.kofo.mpg.de/viewtopic.php?f=8&t=5018&p=21189&hilit=OfakeG#p21189). I followed the documentation but I was unable to convert the file type. I got an error saying the application couldn't find the file.

1) Output File

2) Screenshot of Avogadro window

3) Screenshot of OfakeG application window

I learned from somewhere that ORCA is the most popular free and open-source computational quantum chemistry software developed by Frank Neese and others. Now, being a language enthusiast, I want to go through the package's source code. But I couldn't find that in GitHub or GitLab. The ORCAQuantumChemistry GitHub organization has only one repository with a collection of 'compound scripts' for use with the ORCA quantum chemistry software. Searching on Google also couldn't give me a result. Can anyone help me by providing the link to the source code?