A Modern-Fortran Program for Chemical Kinetics on Top of Anharmonic Vibrational Calculations

We discuss the design and implementation of StarRate, a modern-Fortran program for the calculation of chemical kinetics coupled to anharmonic vibrational perturbative treatments. The program is written in the F language, a carefully crafted subset of Fortran 95, and is conceived in an object-based programming paradigm, i.e. the set of object-oriented programming features supported by Fortran 90/95. StarRate is made up of three main modules handling the involved molecular species, the elementary reaction steps, and the whole reaction scheme. Input data are accessed through an XML interface based on a cross-code hierarchical data format granting interoperability with popular electronic-structure packages and with the graphical interface of the Virtual Multifrequency Spectrometer developed in our group. Data parsing is performed through versatile Python scripts. Test calculations on the isomerization reaction of C-cyanomethanimine using anharmonic densities of states obtained with a development version of Gaussian are reported together with an account of ongoing developments.