ICM User's Guide: Color by Quantum Mechanical Electrostatic Potential

This option colors an existing molecular surface according to the quantum-mechanical electrostatic potential calculated using Psi4. The default calculation method is B3LYP/6-31G*. The electrostatic potential is calculated at each point of the surface and displayed using the following color scheme:

Red: Negative electrostatic potential, indicating electron-rich regions.
Blue: Positive electrostatic potential, indicating electron-poor regions.
White: Intermediate values.

The calculation uses a single molecule and its existing geometry.

Select the chemical in the ICM workspace.
MolMechanics/Quantum Mechanics/Color by QM Electrostatic Potential
If you already have a surface built you can color tjat or ICM will build a new one.

The color scale is automatically adjusted to the minimum and maximum potential values on the surface. Alternative functionals, basis sets, and color schemes can be specified via the command line.