Input for example mol scaleminmax 0 1 -0.06 0.06 in VMD console window, where -0.06 and 0.06 are your expected lower and upper limits of color scale. Also you can directly modify the .vmd plotting script provided in Multiwfn package to adjust default color scale range.

ok Thank you
Another question...
When I plot the ESP map (RGB), most of the molecule is dark blue. How can I adjust the range of the Red/Blue in VMD?

I strongly do not recommend invoking cubegen in this situation, because the time consuming will be higher. The ESP code in Multiwfn of latest version is never slower than cubegen for this purpose, and when built-in ESP code is used, a special treatment is automatically used to significantly reduce cost.

Regarding the number of points to be calculated, it is controlled by the commands in ESPiso.txt:

5
1
3 <---- High quality grid for evaluating electron density
2
0
5
12
1 <---- Medium quality grid for evaluating ESP, which is much more expensive than evaluating electron density
2

Thank you for your answer.
I followed the tutorial on YouTube to plot the reference figures (https://www.youtube.com/watch?v=QFpDf_GimA0). However, instead of using the scripts, that are Windows functions (like move instead of mv), I typed the commands on Terminal. When I typed the first command (Multiwfn 1.fchk -ESPrhoiso 0.001 < ESPìso.txt), it ran several steps. One of these steps is the cubgen. Is there a way to increase the points during cubgen run?

Please carefully clarify how did you plot the electrostatic potential surface. Multiwfn has extremely flexible functions in analyzing ESP, there is no unique way of plotting this map.

Dear,

I'm trying to plot the Electrostatic potential surface.
I'm using a Linux OS on a computer without a graphical interface (and without vmd). I'm following the tutorial on the YouTube channel. Is there a way I can increase the points during cubegen run? When I use cubegen by myself, the command is cubegen.... 300 -h, but I think the Multiwfn uses less points...

Thank you for your help