CFF

Contents

Release 97.0, October 1997

Table of Contents

1. Introduction

Organization of this documentation

What is a class II forcefield?

Range of applications

Access from the Insight® II interface

Product description

2. Theory and Implementation

Quantum mechanical forcefields

Internal energy terms

Energy functional forms

Energy surface sampling

Empirical scaling

Validation of the CFF forcefield

Available functional groups

3. Methodology

Pulldowns

Options in the Assign_CFF parameter block

Potential_Action

Partial_Chg_Action

Formal_Chg_Action

Assembly/Mol_Name

Defining and entering a model

Charge and atom type assignments

Checking for undefined parameters and atom types

Adding new parameters

Other potential types of errors/problems/limitations

Use with solvation models

4. Tutorial

Getting started

Sample computation using CFF

Where to look for missing parameters

Obtaining new parameters

Adding new parameters to the .frc forcefield file

Reassigning the CFF forcefield

Results of simple minimization using the revised forcefield

5. References

A. CFF Quantum Mechanical Data Sampling Statistics

B. List of Atom Types

C. CFF Publications