DFT modelling of graphene, fullerenes, nanotubes etc

[mic*]

Hi all. Does anyone here have any experience modelling graphitic materials using DFT based software (eg VASP)?

I am looking to utilise some simulation results in conjunction with applied research on these materials. The focus is really the applied stuff, and I have very little background in comp-chem.

I was hoping I might be able to get some advice and/or ideas on where to start with software, associated libraries, and other resources.

Cheers.

 

[mic*]

Let me put this another way. I am familiar with the process of literature searching and referencing, but I have no idea what sort of published libraries exist for molecular modelling, or even if there is such a thing, beyond the literature.

If there is such a thing, or anything at all like it, could someone point me in the right direction. I want to sift through existing graphitic models.

Please excuse me if this all seems naive, but I don't have a chemistry background.

 

[TeethWhitener]

You can google "dft materials database" and find a zillion of them:

https://mgi.nist.gov/jarvis-dft
http://materials.nrel.gov/
http://chimad.northwestern.edu/research/databases.html

I don't know if there's a single one that the community is converging on as the authoritative database. For molecular calculations, there's CCCBDB (which is pretty authoritative):

http://cccbdb.nist.gov/

 

[mic*]

Thank you TeethWhitener, this is exactly what I meant.

Obviously I didn't hit the right search string in my first couple of attempts looking into this and I just got "asky"...

I did search the forum a bit and noticed you reply on a few dft threads. Do you have any preferences, or advice on how they differentiate from each other?

Eg one might be prefererred for those modelling elemental or small compound molecules, another for crystalline solids?

 

[TeethWhitener]

Thank you TeethWhitener, this is exactly what I meant.

Obviously I didn't hit the right search string in my first couple of attempts looking into this and I just got "asky"...

I did search the forum a bit and noticed you reply on a few dft threads. Do you have any preferences, or advice on how they differentiate from each other?

Eg one might be prefererred for those modelling elemental or small compound molecules, another for crystalline solids?

This is pretty vague. Do you mean a preference for certain programs? Or certain methodologies? Something else?

As far as programs go, I stick to the simple rule: whatever's the cheapest (read: free) and requires the least amount of my time to maintain and keep running on my computer. Abinit and Quantum Espresso are pretty good for materials (I've never used VASP or SIESTA). For molecules (electronic structure), I usually use ORCA but I've used a bunch of different programs in the past (GAMESS, Gaussian, Turbomole, NWChem) and they each have their strengths and weaknesses. For molecular dynamics, I've only ever used NAMD, which I really like, but I don't really do extensive MD calculations.

 

[mic*]

Apologies for vagueness. Despite it, your response is pretty on point. Gives me a bit of research direction. I can't really ask anything more specific until I have a bit of familiarity with abovementioned software and their descriptions etc.

I am not 100% sure how much I need to get into it all yet. My interest relates to papers where dft has been used to calculate approximate ion sizes in various solutions, in various porous carbons and graphitic materials. I just want to understand what has been done and feel capable that I could replicate the published work, if necessary. I need to go back and review the literature again because a lot of the parts relating to dft went straight over my head, can't even be sure what software or correlation functionals were reported, off the cuff...

Having gained a basic understanding of dft and now, from you, a few program names, database locations etc I have plenty to work with.

Cheers.