<![CDATA[Multiwfn forum / signature of BCP in AIM Analysis for SO2]]> http://sobereva.com/wfnbbs/viewtopic.php?id=1784 Tue, 27 Jan 2026 16:18:38 +0000 FluxBB <![CDATA[Re: signature of BCP in AIM Analysis for SO2]]> http://sobereva.com/wfnbbs/viewtopic.php?pid=5553#p5553 You should check eigenvalues of Hessian of electron density, rather than Cartesian components of Laplacian of electron density. They are different.

]]> Tue, 27 Jan 2026 16:18:38 +0000 http://sobereva.com/wfnbbs/viewtopic.php?pid=5553#p5553 <![CDATA[signature of BCP in AIM Analysis for SO2]]> http://sobereva.com/wfnbbs/viewtopic.php?pid=5548#p5548 Hi
I did a topology analysis of the electron density (= AIM = Bader Analyis) of the SO2 molecule. The analysis finds two symmetry equivalent BCP with signature (3,-1):

Fig1.jpg

However, when I do "7 Show real space function values at specific CP or all CPs" to check the components of the Laplacian, I get only one negative, but two positive eigenvalues:

Fig2.jpg

How can the CP type be (3,-1), when only one of the lambda values is negative?

]]> Tue, 27 Jan 2026 09:46:13 +0000 http://sobereva.com/wfnbbs/viewtopic.php?pid=5548#p5548