Welcome to Quantarhei’s Documentation!

Quantarhei is a Molecular Open Quantum Systems Simulator written predominantly in Python. Its name is derived from the famous aphorism “Panta rhei” of the Greek philosopher Heraclitus of Ephesus. “Panta rhei” means “Everything flows” or “Everything is in flux”, which is quite fitting when you change Panta into Quanta.

In “Quantarhei” the last four letter (“rhei”) should be written in Greek, i.e. (using LateX convention) “\rho \epsilon \iota”.

This page is meant be the complete source of documentation for Quantarhei package. We describe Quantarhei’s main features and the philosophy behind them, together with a complete description of its functionality and content.

Large part of this documentation is based directly on Quantarhei’s source code. Inspecting the source code should be an important part of learning to use Quantarhei. Not only that you can learn to use Quantarhei better by inspecting the source code, but, in a better case, you learn something usefull from how open quantum systems’ problems are solved in Quantarhei. In a worse case, you will be motivated to fix Quantarhei’s deficiencies.

There two types of deficiencies that one can expect in Quantarhei - a mild one: things work well but programming style is terrible, or things are not implemented in a general enough manner. In this case you are most welcome to fix the code. Make sure that your improvement passes all automatic tests. Here we provide a detailed description of the classes provided by Quantarhei.

A more serious defficiency is when you find that something is really implemented wrongly. The best approach then is to write an alternative test code which demonstrates the errors. Submit this to the maintainers and when they agree that the error is real, go ahead to fix it (or get it fixed by the maintainers).

Current status of Quantarhei

Quantarhei’s source code is available from Github, source and binary bundles for easy installation can be found on Pypi and Anaconda Cloud. Latest builds are tested on Github and the test coverage is measured by coverage package and displayed on Codecov Documentation for Quantarhei can be found on Readthedocs. Also the documentaion is build from the source code. Quantarhei is an Open Source software published under the MIT license, which is short and very non-restrictive. At present we are in the alpha stage of the development. Our interim goal is version 0.1.0, for which we are developing a definition (see our Github Wiki page) We expect our package to run on more than the most current version of Python, but at the moment we do not explicitely test it. When installing from Anaconda Clound (recommended) the package supports all major platforms.

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