Fig. 1: Demonstration of the degree distribution in the experimental spectroscopic network of H216O.
From: All paths lead to hubs in the spectroscopic networks of water isotopologues H216O and H218O
The central panel specifies the most important terms and symbols used throughout this study. Panel a shows a typical discrete, heavy-tailed degree distribution. This distribution pertains to a subnetwork of the H216O network reported in ref. 42, where only the pure experimental lines are included, contracting each multiple edge into a single one (for the concrete subnetwork, see Supplementary Data 1). The highest-degree hubs are given with different colors in panel a for the three vibrational bands of the hub list. The degrees d follow an inverse power-law-like model down to \(d\ge {d}_{\min }\)13,16, whose parameters (with their last-digit 1σ uncertainties in parentheses) are also shown in panel a. Panel b illustrates the neighboring states of the (0 0 0)52,3 hub, with wavenumbers on the top horizontal axis and incident nodes presented as colored diamonds, with the colors reflecting their degrees. Panel c depicts the J dependence of the degrees for the P = 0 and P = 1 polyads up to J = 8. In panel c, the states are denoted, instead of points, via their (one-digit) Ka values, the full assignments can be read from the right-hand-side legend.
