concvar: A program solving time-dependent concentration variation for complex reactions

In this article we introduce concvar program, which aims at studying variation of concentrations of various chemical substances in complex reactions over reaction time by numerically solving chemical kinetics equations. Linking relationship and free energies of all minima and transition states in energy profile of the studied reaction are needed as input. Concvar is easy to use, flexible, and significant for both practical research and physical chemistry teaching. Executable files and a detailed manual of concvar can be freely downloaded at http://sobereva.com/soft/concvar.