Multiwfn forum

supreethprasad

Member

Registered: 2018-04-16

Posts: 1

Extended Charge Decomposition Analysis

I have been performing ECDA analysis on a few systems such as FLi---NH3 and MultiWFN reports that -0.2132 electrons are being donated from NH3 à LiF. What is the significance of the (-) sign? I cannot find an explanation in the manual.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,773

Website

Re: Extended Charge Decomposition Analysis

Dear Supreeth,

Assume that FLi is defined as fragment 1, while NH3 is defined as fragment 2, then negative value of ECDA means that net electron transfer is from NH3 to FLi.

It is worth to note that ECDA is meaningless when diffuse functions are used, and it is somewhat better to evaluate amount of charge transfer based on fragment charges computed by proper population analysis methods (e.g. ADCH, Hirshfeld-I, NPA...)

Best wishes,

Dr. Tian Lu

corey.taylor

Member

Registered: 2018-04-05

Posts: 5

Re: Extended Charge Decomposition Analysis

Hi Tian,

In terms of ECDA, would you say that a combined DFT/non-diffuse basis set approach would be valid for a pi-pi system? So, for example, PBE/Def2-TZVPP against two stacked rings (Bz and Bzfuranone).

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,773

Website

Re: Extended Charge Decomposition Analysis

Hi Tian,

In terms of ECDA, would you say that a combined DFT/non-diffuse basis set approach would be valid for a pi-pi system? So, for example, PBE/Def2-TZVPP against two stacked rings (Bz and Bzfuranone).

Hi,

This combination could be used for ECDA, at least there is no problem in principle.

Tian