Multiwfn forum / Calculation of solubility parameter from ESP

Re: Calculation of solubility parameter from ESP

dummy@example.com (julieborah66) — Sat, 15 Dec 2018 19:19:15 +0000

Thank you Sir for your answer. I will surely do the protocol as mentioned.

Re: Calculation of solubility parameter from ESP

dummy@example.com (sobereva) — Sat, 15 Dec 2018 12:25:13 +0000

Assume that you have mol.fch and mol.chg, the latter contains atomic charges calculated based on the wavefunction carried by the former. To check ESP produced by the atomic charges on electron density isosurface, you should do following things in Multiwfn:

1 Load mol.fch into Multiwfn
2 Enter main function 12
3 Choose "2 Select mapped function"
4 Select "3 Electrostatic potential from atomic charges"
5 Input "mol.chg"
6 Choose option 0 to start analysis

Then in the analysis, wavefunction in mol.fch will be used to construct electron density isosurface, while ESP will be calculated based on the atomic charges in the mol.chg file.

Re: Calculation of solubility parameter from ESP

dummy@example.com (julieborah66) — Sat, 15 Dec 2018 09:55:46 +0000

I want to check if the point charges are used in the forcefield parameters will they be able to predict the solubility parameter (calculated by ESP) near to experimental values.

Re: Calculation of solubility parameter from ESP

dummy@example.com (sobereva) — Sat, 15 Dec 2018 04:24:33 +0000

Is there any special reason that you have to use atomic charges to evaluate ESP on vdW surface? To predict solubility parameter, commonly better ESP quality will result in better prediction accuracy.

Re: Calculation of solubility parameter from ESP

dummy@example.com (julieborah66) — Fri, 14 Dec 2018 11:27:59 +0000

Is there any way out by which we can calculate the electrostatic potential map generated by the atomic charges which could assist to find out the solubility parameter?

Re: Calculation of solubility parameter from ESP

dummy@example.com (sobereva) — Fri, 14 Dec 2018 10:34:29 +0000

This way is unviable. The main reason is that, the .chg file doesn't contain wavefunction information, therefore in main function 12, it is unable to construct vdW surface based on electron density isosurface.

Calculation of solubility parameter from ESP

dummy@example.com (julieborah66) — Fri, 14 Dec 2018 08:51:36 +0000

I want to calculate the solubility factor from the ESP map as stated in (J. Mol. Struct. (THEOCHEM), 307, 55), but by taking the .chg file from a set of atomic charges.

Is it possible to do in Multiwfn, using the following procedure.

1. A .chg file loaded of the molecule
2. and going to the main function 12, Quantitative analysis of molecular surface
3. going to 0 Start the analysis.
4. Getting the product of total esp variance and degree of charge balance
5. Calculating the solubility parameter.