CRYSTAL (software)

CRYSTAL (software)
Name	CRYSTAL
Developer	University of Turin, CNR, CECAM
Released	0 1988
Programming language	Fortran
Operating system	Linux, Unix, macOS
Genre	Computational chemistry

Contents

Overview
Features and capabilities
Theoretical foundations
Applications
Development and history
See also

CRYSTAL (software). CRYSTAL is a prominent quantum chemistry program designed for performing ab initio calculations on crystalline systems. It is a specialized tool within the broader field of computational materials science, enabling the study of the electronic structure and properties of periodic solids. The software is developed and maintained by an international consortium led by institutions in Italy and is widely used in both academic and industrial research.

Overview

CRYSTAL is a specialized software package for performing Hartree–Fock and density functional theory calculations on periodic systems. It is a cornerstone tool for researchers investigating the properties of crystals, polymers, and surfaces. The program's core functionality is built upon the linear combination of atomic orbitals method, adapted for infinite periodic lattices. Its development has been significantly supported by organizations like the Italian National Research Council and the European Centre for Atomic and Molecular Calculations.

Features and capabilities

The software provides a comprehensive suite for calculating key properties of solids, including band structure, density of states, and elastic constants. It can perform geometry optimization for crystal structures and simulate various spectroscopic properties, such as infrared and Raman spectra. CRYSTAL supports hybrid functionals, like B3LYP, and can handle systems with spin–orbit coupling. It is interoperable with other major codes in the field, such as VASP and Quantum ESPRESSO, for specific workflows. The program includes capabilities for modeling defects in crystals and low-dimensional systems like nanotubes.

Theoretical foundations

The program's methodology is rooted in the solution of the Schrödinger equation for periodic potentials using a basis set of Gaussian-type orbitals. It implements both the Hartree–Fock method and various density functional theory approximations to describe electron correlation. The treatment of the Coulomb interaction in infinite systems employs sophisticated techniques like the Ewald summation. Its approach to Bloch's theorem allows for the efficient calculation of electronic wavefunctions across the Brillouin zone. The development of its algorithms has been influenced by the work of prominent theorists in solid-state physics and quantum chemistry.

Applications

CRYSTAL is extensively applied in the study of minerals, zeolites, and semiconductor materials for predicting their structural and electronic behavior. It is used in the design of new catalytic materials and in research related to energy storage, such as lithium-ion battery electrodes. The software aids in the interpretation of experimental data from facilities like the European Synchrotron Radiation Facility. It has been employed in pharmaceutical research to understand the properties of molecular crystals and polymorphism. Studies on high-temperature superconductivity and topological insulators have also utilized its computational framework.

Development and history

The CRYSTAL project originated in the late 1980s at the University of Turin and the CNR institute in Torino. Its first public release occurred in 1988, establishing it as one of the first widely available codes for periodic ab initio calculations. Major algorithmic advancements were made throughout the 1990s, including the implementation of density functional theory and analytic gradient methods. The developer consortium expanded to include groups from the United Kingdom, Spain, and Germany. Ongoing development focuses on improving performance for large-scale systems and enhancing user accessibility through graphical interfaces.