the unit of electron density in Dmol3?

Dear everyone,

Please help me!

I have plotted a figure of the total electron density isosurface with isovalue of 0.2.

What is the unit of the isovalue?

I also tried to use the color mapping, and the mapped field was electrostatic potential field.

Then, I've got something like the pic below.

I wonder what is the unit of the values in the legend?

QQ截图未命名.jpg