The reliability of the random phase approximation (RPA) and of σ-functional methods in conjunction with the mixed Gaussian and plane wave (GPW) basis set scheme

Nonadiabatic molecular dynamics simulations provide a theoretical understanding of various excited-state processes in photochemistry, offering access to band widths, radiative or nonradiative relaxation and corresponding lifetimes, excited-state energies, and charge transfer. The range of method developments within the framework of time-dependent density functional theory is exceedingly large for molecular quantum chemistry. Still, it shrinks significantly when aiming to treat periodic boundary conditions. To address this gap and complement existing software packages for solid-state nonadiabatic molecular dynamics, we present an interface between the CP2K electronic structure and the NEWTON-X surface hopping codes. The interface features the generation of initial conditions, as well as adiabatic and nonadiabatic molecular dynamics, based on phenomenological or numerical time-derivative couplings. Setups are validated on gas-phase pyrazine, with electronic absorption spectra and excited-state populations for transitions between the lowest singlet states being in agreement with established molecular quantum chemistry methods. Extending the system size to crystalline pyrazine, limitations of approximate couplings are discussed, and the efficiency and applicability of the interface are demonstrated by computing broad spectra over several eV and 100 fs trajectories, considering couplings between all 80th lowest excited states, at low computational cost with a mixed semiempirical density functional theory setup.

We employed ab initio Born−Oppenheimer molecular dynamics in order to reveal the explicit solvation effects of methanol and water on the tautomeric eq…

CP2K is a versatile open-source software package for simulations across a wide range of atomistic systems, from isolated molecules in the gas phase to low-dimensional functional materials and interfac...

We develop constrained nuclear-electronic orbital density functional theory (CNEO–DFT) with periodic boundary conditions, enabling simultaneous quantum mechanical treatment of both electrons and nucle...

Note This is the last release with a GNU Makefile. Please migrate to CMake. New Features TDDFPT: Add exciton descriptors (#3847) Efield implementation for xTB (#3883) Atom code: Add option to wri...

MiMiC is a framework for modeling large-scale chemical processes that require treatment at multiple resolutions. It does not aim to implement single-handedly all methods required to treat individual subsystems, but instead, it relegates this task to specialized computational chemistry software while it serves as an intermediary between these external programs and computes the interactions between the subsystems. MiMiC minimizes issues typically associated with molecular dynamics performed with multiple programs by adopting a multiple-program multiple-data paradigm combined with a loose-coupling model. In this work, we present the addition of a new client program, CP2K, to the MiMiC ecosystem. Moreover, to align the implementation of MiMiC with its modular philosophy, we performed a major refactoring of the entire framework. This endeavor unlocks its full flexibility and reduces any future efforts for introducing new programs to a minimum. Furthermore, by thorough timing analysis, we verify that the introduced changes do not affect the performance of MiMiC or CP2K, and neither are they a source of significant computational overheads that would be detrimental to simulation efficiency. Finally, we demonstrate the benefits of the framework’s modular design, by performing a QM/MM MD simulation combining CP2K with previously interfaced OpenMM, with no additional implementation effort required.

Some initial results on the reactivity of a primal carbon cluster towards ammonia in space, Kalchevski, Dobromir Antonov, Trifonov, Dimitar, Kolev, Stefan Kolev, Popov, Valentin, Aleksandrov, Hristiyan, Dimov, Dimitar Angelov, Milenov, Teodor Ivanov

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Date: 13 May 2025 Time: 15:00 CEST Registration   Abstract These days, computational chemists can choose from a wide variety of software packages, each with its own unique features and strengths. Man...

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