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julieborah66

Member

Registered: 2018-09-17

Posts: 32

Control Grid spacing,Extension distance (in 3directions) in ESP

Dear Sir,

I have a small query, Is it possible to have a control over the grid points and Extension distance ( in x, y and z directions) from the molecule in calculation of ESP? Will change in the settings.ini in Aug3D would serve the purpose for the extension distance? Do we have an input variable for grid spacing too in settings.ini?

Last edited by julieborah66 (2020-02-28 16:44:30)

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,770

Website

Re: Control Grid spacing,Extension distance (in 3directions) in ESP

Multiwfn provides extremely flexible options to control distribution of grid points, the number of grid points or grid spacing can be fully customized via corresponding options. In the grid setting interface, you can directly set extension distance around the molecule via option "-10 Set extension distance of grid range for mode 1~4", while the "aug3D" in settings.ini defines the default extension distance.

I strongly suggest you check Section 3.6 of manual, in which the various modes in Multiwfn for defining grids are explained in detail.

julieborah66

Member

Registered: 2018-09-17

Posts: 32

Re: Control Grid spacing,Extension distance (in 3directions) in ESP

Thank you, Sir, I am doing example 4.7.8 of the manual, Examine electrostatic potential reproducibility of atomic charges, is there a way to control the grid spacing in RMSE comparison of a particular atom? and what is the default grid spacing if not set? I need a 5 Angstrom extension distance around the molecule. So, I changed in Aug 3D (converting Angstrom to Bohr 9.44 Bohr) and I want 0.3 Angstrom grid spacing.

Last edited by julieborah66 (2020-02-29 09:41:29)

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,770

Website

Re: Control Grid spacing,Extension distance (in 3directions) in ESP

Please note that the concept of "grid spacing" is inapplicable to MK calculation, which is involved in Section 4.7.8. The MK type of grid points are distributed over different shells of molecular surface, only "density" of MK points over the surfaces can be controlled (via option "2 Set number of points per Angstrom^2")

julieborah66

Member

Registered: 2018-09-17

Posts: 32

Re: Control Grid spacing,Extension distance (in 3directions) in ESP

Thank you, Sir, for your prompt reply. So, is there a way in Multiwfn to get RMSE and RRMSE of a certain atom using a set of charges specified by the user but the user has control over the grid points in ESP like spacing and extension distance? Actually I am trying to implement a procedure as given in the paper--- Kramer, C., Spinn, A., and Liedl, K. R. “Charge anisotropy: Where atomic multipoles matter most”. Journal of Chemical Theory and Computation, 10(10), pp. 4488–4496 (2014)

Last edited by julieborah66 (2020-03-01 05:14:01)

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,770

Website

Re: Control Grid spacing,Extension distance (in 3directions) in ESP

Extension distance and grid spacing are only defined for CHELPG type of grid, please check Section 3.9.10 for definition of CHELPG type of grid. To use this this type of grid, you should enter CHELPG module (subfunction 12 of main function 7), in which you can find two options "2 Set grid spacing" and "3 Set box extension".

julieborah66

Member

Registered: 2018-09-17

Posts: 32

Re: Control Grid spacing,Extension distance (in 3directions) in ESP

Thanks, Sir, I would like to ask one more thing, does the second last column of ESPfitpt.pqr record the ESP values of the point? For example a pqr file

HETATM 1 O MOL A 1 16.939 -15.091 -0.001 -9.94175506 0.100O
HETATM 2 O MOL A 1 17.235 -14.795 -0.001 -9.19897403 0.100O

Last edited by julieborah66 (2020-03-01 17:35:52)

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,770

Website

Re: Control Grid spacing,Extension distance (in 3directions) in ESP

Yes, when you output ESPfitpt.pqr, you can find below prompt from screen:

Done! Fitting points have been exported to ESPfitpt.pqr in current folder. The
"charge" column in this file corresponds to ESP value in kcal/mol. The radius co
lumn is meaningless