Submitting DataSets to CollisionDB

Data may be submitted to the CollisionDB database using the format described below. Please contact for more information about providing datasets.

Submitted text files should be in UTF-8 encoded, plain text format with metadata specified as the following key=value pairs. Some general principles:

In the below, compulsory metadata is indicated by

Basic Metadata


Data are presented in a table of columns of values, delimited by whitespace.


E           sigma
1.250E+01   1.088E-03            # no uncertainty value
1.550E+01   *                    # missing data point
1.229E+01   1.4e-18:5e-19        # symmetric uncertainty, 1.4e-18 ± 5e-19
1.229E+01   1.4e-18:5e-19,8e-19  # asymmetric uncertainty, 1.4e-18 (-5e-19, +8e-19)

An example template file for two-column data is provided here: xy_template1.txt.

Data may also be provided in a table with more than two columns, where each column following the first one contains data for a separate reaction. This is often useful where calculations are carried out for several different reactant or product states in a process. In this case, the reaction metadata key-value pair must indicate a wildcard, (*), into which the column headings will be interpolated to form the full collisional process "reaction".


columns=["E, keV/u", "sigma, 10^-16 cm2"]
reaction="Be+4 + H 1s -> Be+3 (*) + H+"
E        n=1       n=2       n=3
20       3.79E-3   1.05E+0   1.75E+2
100      *         2.93E-1   8.39E-1
500      3.68E-3   3.69E-3   1.63E-3

This table is understood to provide the cross sections for three processes, on the same energy grid for the formation of Be3+ in each of the states n=1, n=2 and n=3. That is, the above data are for the "reactions":
Be4+ + H 1s → Be3+ n=1 + H+
Be4+ + H 1s → Be3+ n=2 + H+
Be4+ + H 1s → Be3+ n=3 + H+

An example template file for multiple-column data is provided here: xy_template2.txt.

Fitting Coefficients

The fitting coefficients along with numerical data (either from the original source or derived from the fit function) can be provided in JSON format in the fit block of metadata, in which the following names may be defined:

An example template file for fitted data is provided here: fit_template.txt.