RADEN Data Bank

The data bank on RADiative and ENergy parameters for diatomic molecules

RADEN Online (Reference-Information-System)

The RADEN data bank produced at the Department of Chemistry of Moscow State University is designed as well to accumulate published information on radiative parameters of diatomic molecules, as to analyse it and recommend the more reliable values.
The bank consists of two parts: Reference-Information-System (RIS) and Recommended-Data-System (RDS) operating under the control of an interactive program.

Reference-Information-System serves for compiling of experimental researches and ab initio calculations of following parameters:

potential curves U(R);
dipole moments M(R) and M(v);
electronic transition moments D(R);
oscillator strengths of vibronic f_v'v'' and vibrational transitions f_v'v'';
lifetimes of excited states t(v);
Einstein coefficients of vibronic A_v'v'' and vibrational transitions A'_v'v'';
Franck-Condon factors Q_v'v''

Reference-Information-System is made up of two databases: information and factual.

INFORMATION DATABASE includes the following data on researches of molecular electronic states and electronic transitions:

studied parameters (among the mentioned above);
form of the results presentation (plot, table, analytical),
methods and scopes of research,
bibliographic citations.

Now these data are compiled for about 1700 electronic states and about 1900 electronic transitions of approximately 350 diatomic molecules. The database bibliography covers above 3500 publications from 1960 up to the present.

FACTUAL DATABASE lists the numeric results from original publications. Now it is evolved for several hundreds of molecular systems and transitions.

Recommended-Data-System serves to accumulate and calculate recommended values of radiative and energy parameters of diatomic molecules.

The system accumulates:

dipole moments,
transition dipole moments,
ab initio intramolecular potentials,
molecular constants (Dunham coefficients)

The system calculates:

probabilities of vibronic and vibrational transitions (Einstein coefficients),
oscillator strengths of vibronic and vibrational transitions,
lifetimes of excited states,
Franck-Condon factors.

The accumulated information is kept in the Factual Recommended Database. The calculations are performed by the Application Program Package connected with this database.

FACTUAL RECOMMENDED DATABASE contains now the ab initio and experimental electronic transition moments for more than 250 band systems which belong to more than 100 diatomic molecules. These moments were recommended by our experts as the most reliable. The recommendations were carried out as a result of the joint analysis for the data on all radiative characteristics of corresponding molecules published up to 1999. For all of these systems there are ab initio potentials and/or spectroscopic constants, so user can calculate above-listed radiative characteristics for electronic-vibrational transitions.

Spectroscopic constants (Dunham coefficients) were included in the factual recommended database from the handbooks K.P.Huber and G.Herzberg "Molecular spectra and molecular structure. IV.Constants of diatomic molecules",1979 and "Thermodynamic properties of individual substances", Moscow, Nauka, 1978-1980,(in Russian), or from the original reports and reviews.

THE APPLICATION PROGRAM PACKAGE (APP) of the bank allows:

to construct empirical potentials: Morse, Duncham, Ridberg-Klein-Rees (RKR);
to solve numerically the radial Schroudinger equation;
to evaluate overlap integrals between the vibrational wave functions calculated above: Franck-Condon factors, R-centroids;
using the empirical or/and ab initio dependencies of dipole moments or transition dipole moments on the internuclear distance to calculate matrix elements for vibrational or vibronic transitions and to evaluate oscillator strengths, Einstein coefficients and radiative lifetimes.

Raden database: lakuz@laser.chem.msu.ru
Web interface: wasq@elch.chem.msu.ru