Tutorial 07 | Gaussian PES Scans - Relaxed Scans | Dr M A Hashmi

[@maksudkhan9675]

Thank you so much sir. Great work. Just keep it up.

[@WisdomCenter]

Most welcome

[@ritusaxena707]

How Calculate the potential energy barrier associated with Intra-molecular proton transfer in malonaldehyde?

[@WisdomCenter]

You need to calculate both the structures and see the energy difference

[@manzoorhussain4761]

​@@WisdomCenter Dear Sir, i have scanned structures (relaxed and rigid) for a hydrogen-bonded complex in the ground and excitation state to explore inter-molecular proton transfer mechanism. How can we determine the energy difference from scanning calculation and how much energy barrier is negligible for hydrogen transfer? Would you like to explain, I need your expert view.

[@usman_a_qureshi]

Is it possible to change the PES 3D graph into 2D in gaussian as you shown in the start of this video?

[@WisdomCenter]

If you just have one scanning variable then it will be 2D but if you scan more than one coordinate then it will be 3D

[@usman_a_qureshi]

@@WisdomCenter but I have Gaussian and Gauss View installed in my other computer where the Gauss Views generates two scanning variables in 2D format but the Gauss View in my first computer generating 3D graph. Do you think it’s the issue of software or something like error in software?

[@WisdomCenter]

@@usman_a_qureshi May be you are using log file on one PC and chk file on the other. It can also happen due to different versions of GaussView

[@usman_a_qureshi]

@@WisdomCenter No it’s not. I am using the log files in both cases but getting two different type of spectra which I didn’t understand why it’s happening?

[@biamalik75]

We have to take log file for this purpose and make it gjf ?

[@WisdomCenter]

I don't understand your question!

[@biamalik75]

@@WisdomCenter no worries ,,i got my answer already ,,thankyou for replying ,, My another question is i done PES scan ,but i don't know how to interpret it ,,how to understand it

[@WisdomCenter]

@@biamalik75 There isn't much to worry about understanding. It is basically the energy w.r.t coordinates. It is telling you the energy of different possible combinations of bond lengths and bond angles

[@biamalik75]

@@WisdomCenter okay thankyou please reply me on other video of transition state ,,

[@NTHina]

sir, which software will suitable for porphyrin chemistry or for macromolecule

[@WisdomCenter]

Gaussian can work well

[@siprasucharitasahoo2145]

@@WisdomCenter for bigger molecule like porphyrin it is difficult to freeze all other parameters. then how to do in a simple way?

[@subhassamanta297]

Can't we run this scan without freezing other four dihedral angles?

[@WisdomCenter]

Yes we can

[@basicchemistryplus5788]

Sir, Thank you for these videos. i am facing an issue here, I am getting 2D plots not 3D.

[@WisdomCenter]

If you follow all the steps carefully you should get 3D plots. Remember there should be two different properties combined to get a 3D plot, e.g a bond angle and a bond length. If you have just one property of interest, there will be 2D plot.

[@basicchemistryplus5788]

@@WisdomCenter ok sir. Thanks for the reply

[@JibonorJatrat]

Sir how can we include this pes diagram clearly in our manuscript?

[@WisdomCenter]

You can save it as an image and then insert in your manuscript

[@atazazahsin9993]

A.oA i need ts

[@WisdomCenter]

Then run it

[@atazazahsin9993]

A.oA i need ts

[@WisdomCenter]

Then run it