Simulation of dynamics – both nuclear and electronic - in complex chemical systems is a challenging task. The difficulty arises due to the two main factors: a) the necessity to utilize accurate computational methodologies; b) the necessity to possess a convenient and computationally efficient implementation of such methodologies in a practical tool. It is a common practice to focus only on one of these components. As a result, one often ends up with a novel computational methodology implemented and tested only on selected model problems. Alternatively, one may start with elaborate computational toolbox, but it is often difficult to implement novel techniques into it or develop and test novel methodologies.<br/>In order to merge the two worlds, we have developed a novel open-source platform for “methodology discovery” – the Libra package. The package is organized as a modular library that allows both functional- and object-oriented approaches to utilization of its content. The code is developed with the transferability, reusability, and flexibility criteria in mind. The library or any of its sub-collections can be imported into Python-based scripts as Python modules. The components can also be used within the low-level C++ codes. The modularity and object-oriented design of the library make its usage simple, even for non-expert users.<br/>In this presentation, I will demonstrate the basic and more advanced capabilities of the code: classical and quantum adiabatic and non-adiabatic dynamics as well as numerous related features. I will demonstrate how one can mix and match various modules of the library to meet his/her objectives. Specifically, I will show how photoinduced dynamics in model and atomistic systems can be simulated even by non-expert users. The “methodology discovery” aspect of the code will be demonstrated on example of the algorithms for adding system-bath interactions and the approaches for entangling trajectories in atomistic nonadiabatic dynamics.<br/>

Libra: An open-source, “methodology discovery” library for quantum and classical dynamics simulations

251st National Meeting (2016)

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