ChemShell tutorials

This page guides you through a series of input scripts for ChemShell. It is intended that they are followed in the order presented, so as to build up simple elements that are then re-used. At all stages, it is recommended that you find the appropriate section of the manual. The manual is searchable so you should be able to take keywords from the examples.

In most cases the pages below correspond to a directory in the directory docs/tutorial/samples of your ChemShell distribution and the examples are provided there with a .py suffix. Providing ChemShell has been set up correctly on your machine, the Unix shell command to run the examples will be:

$ chemsh


In this tutorial a dollar symbol ($) indicates that you should type the command that follows in a Unix shell (rather than in ChemShell). The dollar symbol represents the command prompt and should not itself be typed in.

Python basics

ChemShell is controlled by scripts written in the Python programming language. This is a more flexible and powerful approach than the input files normally used by computational chemistry codes, but does mean you need to know a few simple programming concepts. Although Python is very easy to pick up as you go along, we strongly recommend you familiarise yourself with the basics first in order to understand how ChemShell works.

  1. Python basics

A more detailed Python tutorial is available on the Python website if you would like to learn more of the language.

First steps with ChemShell

This section contains a selection of ChemShell data files illustrating simple tasks such as single-point energy evaluations and geometry optimisation.

  1. Single-point calculations
  2. Energy minimisation
  3. Transition state optimisation
  4. Reaction path optimisation
  5. Classical forcefield calculations
  6. Hybrid QM/MM calculations

Case studies

This section works through more in-depth examples including solid state and liquid-phase systems.

  1. Modelling an MgO surface
  2. Modelling zeolites
  3. Diffusion of Li in MgO
  4. Modelling a P450 enyzme

Further reading

In addition to the tutorials, the ChemShell manual provides a comprehensive guide to the features available in the program.

Further details on the QM/MM computational technique can be found in the ChemShell publications: