How to extract information from Charge Density Different?

Question

I would like to learn more about Charge density different and would like suggestion for how to get any information from the Charge Density Different plots. How accurate it is and if anyone have suggestion on book or articles talking about it. I have been searching and most of the literatures i found only talk briefly about it.

Thank you for your suggestion!

Answer 1

Multiwfn

Multiwfn is a package you can use to obtain a lot of electronic properties from the system wave function.

Major functions of Multiwfn

• Showing molecular structure and viewing orbitals (MO, NBO, natural orbital, NTO, LMO, etc.). Speed of generating orbital graph is extremely fast, and the use is very convenient.
• Calculating real space function in a plane and plot plane map. Supported graph types include filled-color map, contour map, relief map (with/without projection), gradient map and vector field map.
• Topology analysis for any real space function, such as electron density (AIM analysis), Laplacian, ELF, LOL, electrostatic potential and so on. Critical points (CPs) can be located, topology paths and interbasin surfaces can be generated, and then they can be directly visualized in a 3D GUI window or be plotted in plane map.
• Population analysis. Hirshfeld, Hirshfeld-I, VDD, Mulliken, Löwdin, Modified Mulliken (including three methods: SCPA, Stout & Politzer, Bickelhaupt), Becke, ADCH (Atomic dipole moment corrected Hirshfeld), CM5, 1.2*CM5, CHELPG, Merz-Kollmann, RESP (Restrained ElectroStatic Potential), RESP2, AIM (Atoms-In-Molecules), EEM (Electronegativity Equalization Method) and PEOE (Gasteiger) are supported. Electrostatic interaction energy of two given fragments can be calculated based on atomic charges. -Charge decomposition analysis (CDA) and extended CDA analysis. Orbital interaction diagram can be plotted. Infinite number of fragments can be defined.

Real space functions supported by Multiwfn

• Electron density
• Gradient norm of electron density
• Laplacian of electron density
• Value of orbital wavefunction
• Electron spin density
• Hamiltonian kinetic energy density K(r)
• Lagrangian kinetic energy density G(r)
• Electrostatic potential from nuclear / atomic charges
• Electron localization function (ELF) defined by Becke and the one defined by Tsirelson
• Electron delocalization range function EDR(r;d) and orbital overlap distance function D(r).

You can download it from here: http://sobereva.com/multiwfn/download.html
The manual has all the information you need not only about how to use the program but also about the description of each method used (with their references). It has a Quick Start guide and a discussion forum.