Quantum nuclear effects and anharmonicity impact a wide range of functional materials and their properties.One of the most powerful techniques to model these effects is the Stochastic Self-Consistent Harmonic Approxim...Quantum nuclear effects and anharmonicity impact a wide range of functional materials and their properties.One of the most powerful techniques to model these effects is the Stochastic Self-Consistent Harmonic Approximation(SSCHA).Unfortunately,the SSCHA is extremely computationally expensive,prohibiting its routine use.We propose a protocol that pairs machine learning interatomic potentials,which can be tailored for the system at hand via active learning,with the SSCHA.Our method leverages an upscaling procedure that allows for the treatment of supercells of up to thousands of atoms with practically minimal computational effort.The protocol is applied to PdCuH_(x)(x=0−2)compounds,chosen because previous experimental studies have reported superconducting critical temperatures,Tcs,as high as 17 K at ambient pressures in an unknown hydrogenated PdCu phase.We identify a P4/mmm PdCuH_(2)structure,which is shown to be dynamically stable only upon the inclusion of quantum fluctuations,as being a key contributor to the measured superconductivity.For this system,our methodology is able to reduce the computational expense for the SSCHA calculations by~96%.The proposed protocol opens the door towards the routine inclusion of quantum nuclear motion and anharmonicity in materials discovery.展开更多
基金Funding for this research is provided by the National Science Foundation,under award DMR-2136038Calculations were performed at the Center for Computational Research at SUNY Buffalo(http://hdl.handle.net/10477/79221).
文摘Quantum nuclear effects and anharmonicity impact a wide range of functional materials and their properties.One of the most powerful techniques to model these effects is the Stochastic Self-Consistent Harmonic Approximation(SSCHA).Unfortunately,the SSCHA is extremely computationally expensive,prohibiting its routine use.We propose a protocol that pairs machine learning interatomic potentials,which can be tailored for the system at hand via active learning,with the SSCHA.Our method leverages an upscaling procedure that allows for the treatment of supercells of up to thousands of atoms with practically minimal computational effort.The protocol is applied to PdCuH_(x)(x=0−2)compounds,chosen because previous experimental studies have reported superconducting critical temperatures,Tcs,as high as 17 K at ambient pressures in an unknown hydrogenated PdCu phase.We identify a P4/mmm PdCuH_(2)structure,which is shown to be dynamically stable only upon the inclusion of quantum fluctuations,as being a key contributor to the measured superconductivity.For this system,our methodology is able to reduce the computational expense for the SSCHA calculations by~96%.The proposed protocol opens the door towards the routine inclusion of quantum nuclear motion and anharmonicity in materials discovery.
