DEMO 1: simple network, where everything is fine
The general MARVEL format is the following:
First column: transition wavenumber in cm-1
Second column: uncertainty in cm-1
Next NQN columns (user defined, see below): quantum numbers of the upper energy levels
Next NQN columns (user defined, see below): quantum numbers of the lower energy levels
Last column: tag of the line
First column: transition wavenumber in cm-1
Second column: uncertainty in cm-1
Next NQN columns (user defined, see below): quantum numbers of the upper energy levels
Next NQN columns (user defined, see below): quantum numbers of the lower energy levels
Last column: tag of the line