Photo-induced processes play key roles in solar energy and optoelectronic applications of metal halide perovskites, requiring understanding of material’s response to excitation on atomic and nanometer scales. Our non-adiabatic molecular dynamics techniques[1] implemented within time-dependent density functional theory[2-4], allow us to model such highly non-equilibrium response in the time domain and at the atomistic level.

Considering realistic aspects of perovskite structure[5-7], we demonstrate that strong interaction at the perovskite/TiO₂ interface facilitates ultrafast charge separation[8], how dopants can be used to both decrease and increase charge recombination[9-11], that grain boundaries constitute a major reason for charge losses[11-12], that moderate humidity increases charge lifetime, while high humidity accelerates losses[13], that hole trapping by iodine interstitial, surprisingly, extends carrier lifetime[14], that collective nature of dipole motions inhibits nonradiative relaxation[15], that organic cation orientation has a strong effect on inorganic ion diffusion and current-voltage hysteresis[16], that surface passivation with Lewis base molecules decelerates nonradiative charge recombination by an order of magnitude[17], that the experimentally observed dual (hot/cold) fluorescence originates from two types of perovskites substructures[18], that doping with larger cations increases lattice stiffness and slows down nonradiative charge recombination[19], why PbI₂ rich perovskites show better performance[20], that halide composition can be used to control charge relaxation[21], that oxidation states of halide defects strongly influence charge trapping and recombination[22], why perovskites exhibit unusual temperature dependence of electron and hole lifetimes[23], how peroxide chemistry extends carrier lifetimes of perovskites exposed to oxygen[24], that rapid decoherence suppresses charge recombination in multi-layer 2D perovskites[25], that hot-hole cooling controls the initial ultrafast relaxation[26], that spin-orbit interactions greatly accelerate nonradiative dynamics[27], how photoinduced lattice expansion influences optoelectronic properties and carrier dynamics[28], that edges of 2D perovskites promote exciton dissociation and suppress recombination due to unsaturated halide bonds and thermal disorder[29], that soft lattice, low-frequency phonons and defect covalency rationalize tolerance to native defects[30-31], that anharmonicity extends carrier lifetimes at elevated temperatures[32], that Pb dimerization greatly accelerates charge losses[33], that iodine and sulfur vacancy cooperation promotes ultrafast charge extraction at MAPbI₃/MoS₂ interface[34], that MAI termination favors efficient hole extraction and slow charge recombination at MAPbI₃/CuSCN heterojunctions[35], that alkali metals passivating and eliminating halide interstitial defects and extend carrier lifetimes[36], how unsupervised machine learning of nonadiabatic molecular dynamics identifies which structural motifs and atomic motions control charge losses[37], and that ion migration and carrier recombination exhibit strong synergy[38].