## Software

# ABINIT

ABINIT is a suite of programs for materials science, which implements density functional theory, using a plane wave basis set and pseudopotentials, to compute the electronic density and derived properties of materials ranging from molecules to surfaces to solids. It implements density functional theory by solving the Kohn–Sham equations describing the electrons in a material, expanded in a plane wave basis set and using a self-consistent conjugate gradient method to determine the energy minimum. Computational efficiency is achieved through the use of fast Fourier transforms, and pseudopotentials to describe core electrons. As an alternative to standard norm-conserving pseudopotentials, the projector augmented-wave method may be used. In addition to total energy, forces and stresses are also calculated so that geometry optimizations and ab initio molecular dynamics may be carried out. Materials that can be treated by ABINIT include insulators, metals, and magnetically ordered systems including Mott-Hubbard insulators.

# CRYSTAL

Computational tool for solid state physics and chemistry. The CRYSTAL package performs ab initio calculations of the ground state energy, energy gradient, electronic wave function and properties of periodic systems. Hartree-Fock or Kohn- Sham Hamiltonians (adopting an Exchange-Correlation potential following the DFT postulates of ) can be used. Systems periodic in 0 (molecules, 0D), 1 (polymers, 1D), 2 (slabs, 2D), and 3 dimensions (crystals, 3D) are treated on an equal footing. In each case the fundamental approximation made is the expansion of the single particle wave functions ('Crystalline Orbital', CO) as a linear combination of Bloch functions (BF) defined in terms of local functions, i.e. Atomic Orbitals.

# DL_POLY

DL_POLY is a general purpose classical molecular dynamics (MD) simulation software. It is a package of subroutines, programs and data files, designed to facilitate molecular dynamics simulations of macromolecules, polymers, ionic systems and solutions on a distributed memory parallel computer.

# FLUKA

FLUKA is a fully integrated particle physics MonteCarlo simulation package from CERN and INFN. It has many applications in high energy experimental physics and engineering, shielding, detector and telescope design, cosmic ray studies, dosimetry, medical physics and radio-biology. It is used for radiation shielding simulations in the safety group.

# GDFIDL

GdfidL computes electromagnetic Fields in 3D-Structures using parallel or scalar Computer Systems. GdfidL computes Resonant Fields in lossfree or lossy Structures and Time dependent Fields in lossfree or lossy Structures. The Fields may be excited by Port Modes or relativistic Line Charges. The Postprocessor computes from these Fields eg. Scattering Parameters, Wake Potentials, Q-Values and Shunt Impedances.

# GNXAS

The GNXAS package is a computer code for EXAFS data analysis based on multiple-scattering (MS) calculations and a rigorous fitting procedure of the raw experimental data. The main characteristic of the software are: + atomic phase shifts calculations in the muffin-tin approximation based on atom self-consistent relativistic calculations. Account for the neighbors is taken. + Inclusion of inelastic losses through complex Hedin-Lundqvist potential. + Calculation of MS signals associated with two, three, and four atom configurations using advanced algorithms. Use of an advanced fitting procedure that allows: + to fit simultaneously any number of spectra containing any number of edges, + to use directly the raw data without any pre-analysis, + to account for complex background multi-electron excitation features, + to use various model peaks for the pair, triplet and quadruplet distribution functions, including non Gaussian models and extreme cases. In all cases absolute parameters can be fitted, - to treat liquid phase or disordered systems and extract reliable g(r) functions in the short range, - to perform a rigorous statistical error analysis and plot two-dimensional correlation maps, - to provide a flexible scientific tool for EXAFS data analysis where the user has access to every stage of the calculation. - full modularity that makes easy to interface parts of the GNXAS software with other available software.

# GROMACS

GROMACS (GROningen MAchine for Chemical Simulations) is a molecular dynamics and energy minimization package mainly designed to simulate the Newtonian equations of motion for systems with hundreds to millions of particles, typically of proteins, lipids and nucleic acids. GROMACS can run on CPUs and GPUs.

# Materials Studio

Materials Studio is a modeling and simulation environment designed to allow to predict and understand the relationships of a material’s atomic and molecular structure with its properties and behavior. With it one can construct, manipulate and view models of molecules, crystalline materials, surfaces, polymers, and mesoscale structures. Materials Studio includes quantum, atomistic (or “classical”), mesoscale, and statistical methods that enable one to evaluate materials at various particle sizes and time scales. It also includes tools for evaluating crystal structure and crystal growth.

# MXAN

MXAN performs a quantitative analysis of the XANES energy range. This is based on a comparison between experimental data and many theoretical spectra that are calculated by varying selected structural parameters of an initial putative structure, i.e. a well defined initial geometrical configurations around the absorber. Hundreds of different geometrical configurations are needed to obtain the best fit of the experimental data. The calculations are performed in the energy space without involving any Fourier transform algorithm; polarized spectra can be easily analysed because the calculations are performed within the full multiple scattering approach. Recently, MXAN has been developed in the framework of the multiple scattering theory and successfully applied to the analysis of several system, both in solid and liquid state. The MXAN procedure,encompasses also the phenomenological broadening and the electronic charge fitting.

# OASYS

OASYS (OrAnge SYnchrotron Suite) is an open-source Graphical Environment for optic simulation software packages used in synchrotron facilities, based on [Orange 3](http://orange.biolab.si/orange3/). It includes SHADOWOUI, a port to the [SHADOW](https://github.com/srio/shadow3) ray-tracing code and XOPPY (the Python version of [XOP](http://www.esrf.eu/Instrumentation/software/data-analysis/xop2.4)

# OCEAN

OCEAN is a versatile package for performing first-principles calculations of core edge spectroscopy. The many-body method is based on ground-state density-functional theory (DFT) and uses the Bethe-Salpeter equation. OCEAN utilizes the programs ABINIT or QuantumESPRESSO for ground-state DFT portion of the calculations. OCEAN is capable of producing various spectra including X-ray absorption near-edge spectra (XANES), X-ray emission spectra (XES), and non-resonant inelastic X-ray scatter (NRIXS or XRS). OCEAN is the result of collaboration between the Rehr group at the University of Washington and Eric Shirley at the National Institute of Standards and Technology (USA).

# Quantum Espresso

Quantum ESPRESSO (QE) is an integrated suite of Open-Source computer codes for ab initio quantum chemistry methods of electronic-structure calculations and materials modeling at the nanoscale. It is based on density functional theory, density functional perturbation theory, plane wave basisi sets, and pseudopotentials. The core plane wave DFT functions of QE are provided by the PWscf (Plane-Wave Self-Consistent Field) component,

# SASfit

SASfit has been written for analyzing and plotting small angle scattering data. It can calculate integral structural parameters like radius of gyration, scattering invariant, Porod constant. Furthermore it can fit size distributions together with several form factors including different structure factors. Additionally an algorithm has been implemented, which allows to simultaneously fit several scattering curves with a common set of (global) parameters. This last option is especially important in contrast variation experiments or measurements with polarised neutrons. The global fit helps to determine fit parameters unambiguously which by analyzing a single curve would be otherwise strongly correlated.

# SPR-KKR

The SPRKKR band structure package allows to calculate the electronic structure of arbitrary 3-D periodic systems, including systems with chemical disorder. The treatment of 2-D periodic systems (e.g. surfaces) can be done at the moment only by using an auxiliary system having three dimensional periodicity or by making use of the cluster approximation. The electronic structure calculation can be done in a non-relativistic, scalar-relativistic as well as fully relativistic mode. In the scalar-relativistic mode paramagnetic as well as spin-polarized systems can be treated, including non-collinear spin structures and arbitrary spin spirals. In the fully relativistic mode, paramagnetic as well as spin-polarized systems with an arbitrary spin configuration can be dealt with. On the basis of the electronic structure calculation, many different properties can be investigated with a strong emphasize on response functions and spectroscopic properties.

# VASP

VASP is an ab initio simulation package based on DFT. It is used for atomic scale materials modelling, e.g. electronic structure calculations and quantum-mechanical molecular dynamics from first principles. VASP computes an approximate solution to the many-body Schrödinger equation, either within density functional theory (DFT), solving the Kohn-Sham equations, or within the Hartree-Fock (HF) approximation, solving the Roothaan equations. Hybrid functionals that mix the Hartree-Fock approach with DFT are implemented as well. Furthermore, Green's functions methods (GW quasiparticles, and ACFDT-RPA) and many-body perturbation theory (2nd-order Møller-Plesset) are available. Central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane wave basis sets. The interactions between the electrons and ions are described using norm-conserving or ultrasoft pseudopotentials, or the projector-augmented-wave method. To determine the electronic ground state, VASP makes use of efficient iterative matrix diagonalisation techniques, like the residual minimisation method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled to highly efficient Broyden and Pulay density mixing schemes to speed up the self-consistency cycle.