# Getting started with ARC¶

## IPython notebook with examples¶

Rydberg atoms - a primer introduces Rydberg atoms and ARC package, and is a good starting point to learn how to use ARC to get relevant information about alkali metal Rydberg atoms. Notebook can also be downloaded in .ipython format here, and can be interactively then modified and used in a Jupyter.

## On demand examples from online Atom calculator¶

Online version also generates the correct code necessary for answering the questions you ask, which can be downladed and used as a starting point for running the package locally on your computer.

If you have a question how to do a common calculation, we recommend checking above mentioned Rydberg atoms - a primer IPython notebook. For general questions about the package usage check here:

1. How to save calculation (or matrix) for later use?

Calculations of pair-state interactions PairStateInteractions and Stark maps StarkMap can be easily saved at any point by calling alkali_atom_functions.saveCalculation . This can be loaded later by using alkali_atom_functions.loadSavedCalculation and calculation can be continued from that point.

2. How to export results?

If you want to export results e.g. for analysis and plotting in other programs, you can use calculations_atom_pairstate.PairStateInteractions.exportData and calculations_atom_single.StarkMap.exportData to export results of Stark map and Pair-state interaction calculations in .csv format. See documentation of corresponding functions for more details.

3. Calculation is not outputting anything? How long does it take for calculation to finish?

Most of the functions have progressOutput and debugOutput as an optional parameter (by default set to False) - check documentation of individual functions for details. We recommend setting at least progressOutput=True so that you have minimum output about the status of calculations. This often displays percentage of the current calculation that is finished, that you can use to estimate total time. Setting debugOutput=True outputs even more verbose output, like states in the selected basis, and individual coupling strengths etc.