# APBS flat-file parameter format¶

This parameter file format is a series of lines of the form:

Residue_name Atom_name Charge Radius Epsilon


where the whitespaces are important and denote separation between the fields. The fields here are:

Residue_name
A string giving the residue name, as provided in the PDB file to be parametrized.
Atom_name
A string giving the atom name, as provided in the PDB file to be parametrized.
Charge
A float giving the atomic charge (in electrons).
Radius
A float giving the atomic radius (in Å).
Epsilon
A float giving the Lennard-Jones well depth (epsilon, in kJ/mol). This is used for the calculation of WCA energies in apolar solvation energies and forces. We assume that the Lennard-Jones potential is defined in the “AMBER style”