How to Finish a Relaxed Surface Scan Before Getting Old!

[@hong-zhouye45]

Thank you so much for sharing! A quick question: do you know how to restart a relaxed scan calc if it crashes before finishing?

[@niconeuman]

you can only do it manually. pick the last structure and set up a new scan starting from the last distance you got to, and adjust the number of steps if you want in order to keep the same spacing as before. the problem is that the list with all energies is only printed at the end, so you will have to find and copy manually the energies for each relaxed geometry from the failed scan.

[@hong-zhouye45]

@@niconeuman Thank you for your reply! That was what I did in the end haha. And for those who see this thread in the future you can grep converged energy by grep "HAS CONVERGED" [outputfile] -B200 | grep "FINAL SINGLE".

[@niconeuman]

@@hong-zhouye45 yes greping is very important when doing calculations

[@Gottlib]

Thanks for your video. Can this method be applied to ES PES?

[@niconeuman]

hi, I think so. you would have to do TDDFT and choose an excited state using iroot 1 or something like that. there may be difficulties but you could try it. how to do excited state optimizations is described in the manual

[@thebongchemist3513]

Hey !! Thanks a lot for such a great and informative video on relaxed surface scan especially on Transition metal containing molecules. I just need a small info that is for these calculations or other calculations what SYSTEM CONFIGURATION you have for your PC. I am ri8 now building one. Tha ks in advance.

[@niconeuman]

Hi, thanks for the comment! I don't use my own computer to run calculations. I use a cluster from my Institute. I don't know the processors it uses but each node has 20 cores and around 120 GB of RAM. I also have access to 1 TB of hard drive, which I assume is SSD. I cannot give much advice on what system to buy, but my guess is that for calculations you should try to have as much memory (size and speed) as you can. besides that try to buy a CPU with 6 or 8 physical processors. orca does not use GPU afaik so don't spend all your budget on the GPU. hope this helps

[@ayyanghosh6575]

Hey, can you please tell me ,how are you adding those explicit water molecules?

[@niconeuman]

I added them in Chemcraft, in near positions, and then I optimized the structure.