Multiwfn forum

youngsam

Member

Registered: 2021-11-10

Posts: 1

Bond order analysis for VASP

Hi,
It's nice to hear about recent developments that Multiwfn can accept VASP files as input, like CHGCAR, WAVECAR, etc.
Thanks for your hard works!

My question is how I can do the bond order analysis through Multiwfn with VASP output files?
An error appears no matter what method of bond analysis (9) is used with the CHGCAR file as input. The error is:
"Error: The input file you used does not contain basis function information! Please check Section 2.5 of the manual for explanation"

As far as I know, CHGCAR file does not contain any wavefunction information. I guess this is why the error occurs but I don't know how to solve it. Is there a way to get the bond order from VASP output files using Multiwfn?

Thank you in advance.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,788

Website

Re: Bond order analysis for VASP

I am sorry to disappoint you. Multiwfn does't support performing any analysis based on wavefunction for VASP. Indeed, Multiwfn is able to read, write, manupulate grid data of VASP, but this doesn't mean Multiwfn is able to deal with wavefunction generated by VASP. Also, there is no plan to support wavefunction analysis for VASP in the near future.

If you need to perform analysis for periodic wavefunction, I strongly suggest you using CP2K to carry out the calculation, and use the molden file exported by CP2K as input file of Multiwfn; however, note that, limited functions have fully supported periodic systems, see Section 2.9.2 of Multiwfn manual for detail. Regarding bond order analysis, currently these are supported (more will be available in future versions): Mayer bond order, multicenter bond order, Wiberg bond order, Mulliken bond order and its decomposition analysis, orbital occupancy-perturbed Mayer bond order.

PS: CP2K is freely available, very fast, and using CP2K is quite simple, as Multiwfn is able to directly generate CP2K input files for common tasks (load a file containing geometry information into Multiwfn, e.g. cif file, then input CP2K in main menu, you will enter the function for generating CP2K input file, a blog article has described this aspect in detail: http://sobereva.com/587)

The reason why CP2K has been supported is because it is based on Gaussian type function, this feature is the same as most mainstream quantum chemistry code; in contrast, VASP is based on plane-wave basis functions to represent wavefunction, it is quite difficult to support under the current framework of Multiwfn.