PySurf: A Framework for Database Accelerated Direct Dynamics

Abstract

The greatest restriction to the theoretical study of the dynamics of photoinduced processes is computationally expensive electronic structure calculations. Machine learning algorithms have the potential to reduce the number of these computations significantly. Here, PySurf is introduced as an innovative code framework, which is specifically designed for rapid prototyping and development tasks for data science applications in computational chemistry. It comes with powerful Plugin and Workflow engines, which allows intuitive customization for individual tasks. Data is automatically stored through the database framework, which enables additional interpolation of properties in previously evaluated regions of the conformational space. To illustrate the potential of the framework, a code for nonadiabatic surface hopping simulations based on the Landau−Zener algorithm is presented here. Deriving gradients from the interpolated potential energy surfaces allows for full-dimensional nonadiabatic surface hopping simulations using only adiabatic energies (energy only). Simulations of a pyrazine model and ab initio-based calculations of the SO 2 molecule show that energy-only calculations with PySurf are able to correctly predict the nonadiabatic dynamics of these prototype systems. The results reveal the degree of sophistication, which can be achieved by the database accelerated energy-only surface hopping simulations being competitive to commonly used semiclassical approaches.

The Newton-X platform: new software developments for surface hopping and nuclear ensembles

“…The dynamics is carried out using conventional DC-FSSH. After the simulations are finished, ensemble averages are computed by translating the initial time of each trajectory to span the whole illumination window and weighting each trajectory by the field-induced initial-state population [eq (10) of reference [25]].…”

Photoredox Chemistry with Organic Catalysts: Role of Computational Methods

“…One such framework, PySurf, includes on-the-fly construction of databases that accelerate the generation of potential energy surfaces. 65 These databases use fitting algorithms to interpolate properties in regions that are already evaluated, and additional quantum chemistry calculations are carried out only when the trajectory leaves the region where these fits are accurate. These advances are expected to significantly reduce the cost barrier to studying excited-state potential energy surfaces and the identification of chromophore features that impact radiationless processes and consequently quantum yields.…”

“…Recent efforts in this field therefore focus on rendering these dynamics approaches more tractable for practical systems. One such framework, PySurf, includes on-the-fly construction of databases that accelerate the generation of potential energy surfaces . These databases use fitting algorithms to interpolate properties in regions that are already evaluated, and additional quantum chemistry calculations are carried out only when the trajectory leaves the region where these fits are accurate.…”

Trendbericht Theoretische Chemie 1/2: Lichtgetriebene Reaktionen unter der Theorielupe

“…Dabei werden in den unbekannten Regionen des Konformationsraums neue Elektronenstrukturrechnungen durchgeführt und mit diesen Resultaten die Datenbank erweitert. 24) In den Regionen, in denen genug Daten verfügbar sind, werden die Näherungsverfahren anstelle der Elektronenstrukturrechnungen verwendet. Dadurch sind keine weiteren, rechenintensiven Berechnungen erforderlich, um die benötigten Eigenschaften zu erhalten.…”

“…2. Pysurf: ein Open-Source-Software-Paket und eine Umgebung für datenbasierte beschleunigte direkte Dynamik 24).…”