The numerical data are presented in two columns where the first column gives the wavelength λ (in nm) (generally in air unless vacuum wavelengths are indicated) and the second column the absorption cross section σ (in cm2 molecule-1) or quantum yield (dimensionless). For the cross sections the engineering notation is chosen, e.g., 1.5e-18 is to be read as 1.5x10-18. Each data set refers to an individual measurement per species and is characterized by the notation:
Structure_Author(Year)_Temperature_Wavelength range,
and in many cases with some additional specification in brackets after the wavelength, e.g.,
CF2ClBr(Halon-1211)_GillotaySimon(1989)_295K_170-302nm(2nm),
CHOCHO_Horowitz(2001)_295K_210-470nm(int-c),
CH2(OH)CH2O2_JenkinCox(1991)_298K_205-290nm(resc).
The graphical representations display the absorption curves, i.e., absorption cross sections σ vs. wavelength λ, or the quantum yield Φ vs. wavelength λ. In contrast to the numerical data sets, the graphical representations compile the available data for a certain species and thus allow comparison of the results from the various individual measurements.
For the spectra, two kinds of plots are presented, the so-called lin-plots and log-plots, with respectively linear and logarithmic scaling of the σ axis. The plots referring to measurements at room temperature and the entire UV-VIS wavelength range covered by the various experiments are characterized by the notation
Structure_lin.JPG or Structure_log.JPG,
e.g.,
CH2Br2_lin.JPG or CH2Br2_log.JPG
Additional specifications such as a particular wavelength range, a temperature range, or a publication period are put behind the structure, e.g.,
CH2Br2_250-348K_lin.JPG or CH2Br2_250-348K_log.JPG,
CH2Br2_VUV_lin.JPG or CH2Br2_VUV_lin.JPG,
Br2_504-553nm_lin.JPG
O3_Chappuis_400-800nm(1986-2003)_lin.JPG.
For the quantum yields, only lin-plots are used for the presentation of Φ vs. λ.
Search program
Two principally different search programs are offered within the Spectral Atlas:
A search via the classification of the species according to well-organized molecular categories and subcategories is to be done under "Catalogue Spectra" or "Catalogue Quantum Yields". After opening this window, the list of molecular categories - currently 33 for the spectra and a few (work in progress) for the quantum yields - appears, which again allows opening for subcategories and/or species. The list of graphical representations and the list of data files arranged according to the name of the first author then appear after selecting a certain species.
A direct search for a species by its molecular structure or name is possible under "Quick search" (only for spectra). A list of the data files corresponding to the wanted molecule appears arranged according to the name of the first author.
Additionally, a quick search for a special author (not necessarily the first author of a publication) also is possible. One will find the list of data files arranged according to the molecular structure of the species studied by this author.
