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Js551

Member

Registered: 2025-08-06

Posts: 2

Electron density integrated into Electron Localization Function basins

Hi. I've been trying to examine the Highest Electron Localization Population (HELP) and Volume (HELV) of valence basins between an actinide atom bonded to four nitrogen atoms. However, I am receiving a lot of interstitial basins around the An core that are making the interpretation of the valence basins difficult.

My procedure, after loading in the complex and viewing the main menu, is option 17, 1, 9 (ELF), 2 (medium quality), an eternity of waiting, option 2, option 1 (electron density). From here, I'm presented with a litany of basins surrounding the An core. An example of this (Plutonium 4+) is attached:

It's blurry, but in the photo, there is a particular basin (148) that lies along the bond path between the Pu(IV)-N bond. This phenomenon is stable across all similar complexes I've observed. However, I'm uncertain about all the other basins lying around the An core and whether or not I should include their data in my analysis, as I'm only interested in the bonding basins between the two atoms. Is there any way to tell if those basins, when HELP and HELV are calculated, should be included for the bonding interaction across these complexes?

Extra: it should be noted that the complex is a chelate. I've only included one basin that is closest to the midpoint of the An-N bond for all analyses thus far. Wiberg bond order between the An-N atoms has been calculated and matches the calculated electron populations for the An(III) series, but diverges with the An(IV) series. An(V) is still being calculated. I have ELF color contour maps made for all complexes as well if that might help. Thank you to anyone who has taken the time to read this post. I really appreciate it.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 2,055

Website

Re: Electron density integrated into Electron Localization Function basins

HELP and HELV, in their original paper, were used to characterize lone pair, it seems that you hope to use them to study bonding ELF basin, this might also make sense but I am not fully sure.

You may visualize other basins surrounding the An to try to identify their meaning, I think they should not be significant and thus can be ignored if your purpose is simply studying bonding.

By the way, to greatly save computational cost of basin analysis of ELF for large systems like this, you can properly define the box when setting up grid so that the box only cover the An atom and coordination atoms around it.

Js551

Member

Registered: 2025-08-06

Posts: 2

Re: Electron density integrated into Electron Localization Function basins

Thank you so much for replying, that's very helpful. As far as defining the box region, how would I go about that? I know of this grid definition section below:

Please select a method for setting up grid
-10 Set grid extension distance for mode 1~6, current: Detect rho isosurface
1 Low quality grid, spacing=0.20 Bohr, cost: 1x
2 Medium quality grid, spacing=0.10 Bohr, cost: 8x
3 High quality grid, spacing=0.06 Bohr, cost: 36x
4 Lunatic quality grid, spacing=0.04 Bohr, cost: 120x
5 Only input grid spacing, automatically set other parameters
6 Only input the number of points in X,Y,Z, automatically set other parameters
7 Input original point, translation vector and the number of points
8 Set center position, grid spacing and box length
9 Use grid setting of another cube file
10 Set box of grid data visually using a GUI window

But I was wondering (if this is the right menu) which option would suit my purposes best.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 2,055

Website

Re: Electron density integrated into Electron Localization Function basins

Detailed description about these modes can be found in Section 3.6 of Multiwfn manual. The most convenient way is using option 10, by which you can visually setting up the box.