Multiwfn forum / Hessian lambda2

Re: Hessian lambda2

dummy@example.com (Quark) — Sat, 25 Jul 2020 15:55:27 +0000

Dear Dr. Tian Lu,
Thank you very much for your help

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Best regards
Eugene

Re: Hessian lambda2

dummy@example.com (sobereva) — Sat, 25 Jul 2020 14:26:54 +0000

Dear Eugene,

Please note that the eigenvalues of Hessian directly printed by Multiwfn are not ordered from most negative to most positive. If you reorder the eigenvalues for CP190 and CP121, you will find the second largest eigenvalues are negative. For example, the lambda2 of CP121 should be -0.02102 rather than 0.12423.

Best,

Tian

Hessian lambda2

dummy@example.com (Quark) — Sat, 25 Jul 2020 11:29:08 +0000

Dear Dr. Tian Lu,

Please tell me why the calculated value of the Hessian lambda2 for critical points 121 and 190 is not negative if the value Sign(lambda2) * rho is negative? I understood correctly that lambda2 is the second Eigenvalues of Hessian?

Thank you in advance for your answers.
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Best regards
Eugene