What is MARVEL?
The acronym MARVEL stands for Measured Active Rotational-Vibrational Energy Levels. MARVEL is based on the concept of spectroscopic networks. The code MARVEL is written in C++ and it is designed for critically evaluating and validating experimental transition wavenumbers and uncertainties collected from the literature as well as for inverting the wavenumber information in order to obtain the best possible energy levels with attached uncertainties in a highly efficient way. MARVEL simultaneously processes all the available assigned experimental lines and determines the associated energy levels for the chosen molecule. In a way MARVEL can invert a 100,000 by 100,000 matrix in a fraction of a second. While the energy levels obtained could be called empirical, in order to emphasize the process they were derived from the evaluated and validated energy levels are usually called MARVEL energy levels.
What is a Spectroscopic Network?
For individual molecules quantum mechanics (QM) offers a simple, natural and elegant way to build large-scale complex networks: quantized energy levels are the nodes, allowed transitions among the levels are the links, and transition intensities supply the weights. QM networks are intrinsic properties of molecules and they are characterized experimentally via spectroscopy; thus, realizations of QM networks are called spectroscopic networks (SN).
The first-principles spectroscopic networks of H2160