Large-Scale Condensed Matter DFT Simulations: Performance and Capabilities of the CRYSTAL Code

Abstract

Nowadays, the efficient exploitation of high-performance computing resources is crucial to extend the applicability of first-principles theoretical methods to the description of large, progressively more realistic molecular and condensed matter systems. This can be achieved only by devising effective parallelization strategies for the most time-consuming steps of a calculation, which requires some effort given the usual complexity of quantum-mechanical algorithms, particularly so if parallelization is to be extended to all properties and not just to the basic functionalities of the code. In this Article, the performance and capabilities of the massively parallel version of the Crystal17 package for first-principles calculations on solids are discussed. In particular, we present: (i) recent developments allowing for a further improvement of the code scalability (up to 32 768 cores); (ii) a quantitative analysis of the scaling and memory requirements of the code when running calculations with several thousands (up to about 14 000) of atoms per cell; (iii) a documentation of the high numerical size consistency of the code; and (iv) an overview of recent ab initio studies of several physical properties (structural, energetic, electronic, vibrational, spectroscopic, thermodynamic, elastic, piezoelectric, topological) of large systems investigated with the code.

Quantum‐mechanical condensed matter simulations with CRYSTAL

“…Here we only briefly address point (b). For a more detailed account on the recent improvements of the massively parallel version of CRYSTAL, we refer to Erba, Baima, Bush, Orlando, and Dovesi (2017). Figure 8 documents the so-called strong scaling of the MPPCRYSTAL program that is the wall-clock time speedup as a function of the number of processors used for a system of fixed size.…”

Quantum Crystallography: Current Developments and Future Perspectives

“…Furthermore, crystallographya lso consists of direct applications of first-principle quantumm echanical methods with periodic boundary conditions (nowadays implemented in world-wide recognized software, such as QuantumE spresso, [69] WIEN2k, [62,71] Crystal, [267] VASP, [268][269][270][271] Turbomole [70] )t os olve problemsins olid-state physics/chemistry. In fact, experiments by themselves can reveal the quantum nature of matter and describe quantum mechanical phenomena( e.g.…”

“…Quantum mechanical modelsh ave always been necessary to interpret the measurements ando vercome the loss of the phase information in the X-ray diffraction data. Furthermore, crystallographya lso consists of direct applications of first-principle quantumm echanical methods with periodic boundary conditions (nowadays implemented in world-wide recognized software, such as QuantumE spresso, [69] WIEN2k, [62,71] Crystal, [267] VASP, [268][269][270][271] Turbomole [70] )t os olve problemsins olid-state physics/chemistry. Nevertheless,w hile the originald efinitiono fQ Cr encompasses only the developments anda pplications of strategies that combine quantum mechanics and experimental scattering in as trictly intertwined protocol, it is evident that other facets of quantum crystallographyf oster ab roadening of its definition.…”

Optical properties of Meloxicam in the far-infrared spectral region

“…Solid-state density functional theory (DFT) simulations were performed using the CRYSTAL17[31] software package. Structural optimizations were done with fixed lattice parameters based on previously published single crystal X-ray data at room temperature[32].…”