  The importance of databases of reliable and accurate data in chemistry has
substantially increased in the past two decades. Their main usage is to
parametrize electronic structure theory methods, and to assess their
capabilities and accuracy for a broad set of chemical problems. The collection
we present here -ACCDB- includes data from 16 different research groups, for a
total of 44,931 unique reference data points, all at a level of theory
significantly higher than DFT, and covering most of the periodic table. It is
composed of five databases taken from literature (GMTKN, MGCDB84,
Minnesota2015B, DP284, and W4-17), two newly developed reaction energy
databases (W4-17-RE, and MN-RE), and a new collection of databases containing
transition metals. A set of expandable software tools for its manipulation is
also presented here for the first time, as well as a case study where ACCDB is
used for benchmarking commercial CPUs for chemistry calculations. To be
published in J. Comput. Chem.
