New features with respect to CRYSTAL17 are in *italics* and red

**Hartree-Fock Theory**- Restricted (RHF)
- Unrestricted (UHF)
- Restricted-Open (ROHF)
- Generalized (GHF), i.e. for a two-component spinor basis

**Density Functional Theory**- Semilocal functionals: local , gradient-corrected and meta-GGA (tau-dependent)
- Collinear Spin DFT
- Non-Collinear Spin DFT
- Spin-Current DFT (SCDFT)
- Hybrid HF-DFT functionals
- Global hybrids: B3PW, B3LYP (using the VWN5 functional), PBE0 and more
- Range-separated hybrids:
- Screened-Coulomb (SC): HSE06, HSEsol, SC-BLYP
- Middle-range (MC): HISS
- Long-range Corrected (LC): LC-wPBE, LC-wPBEsol, wB97, wB97-X, RSHXLDA, LC-BLYP, CAM-B3LYP
- Self-consistent global hybrid functionals (sc-hyb)

- Minnesota semilocal and hybrid functionals:
- M05 family: M05, M05-2X
- M06 family: M06, M06-2X, M06-HF, M06-L
- revised M06 functionals: revM06, revM06-L
- MN15 family: MN15, MN15-L

- SCAN and r2SCAN functionals
- B95-based hybrid functionals: B1B95, mPW1B95, mPW1B1K, PWB6K, PW6B95
- User-defined hybrid functionals
- London-type empirical correction for dispersion interactions (DFT-D2 scheme)
- DFT-D3 correction for dispersive interactions. Automated, parameter-free implementation

- Grimme’s geometrical CounterPoise (gCP) empirical correction to remove the BSSE

- Composite methods for molecular crystals: HF-3c, PBEh-3c, HSE-3c and B97-3c

- Revised composite methods for solid state calculations (HFsol-3c, PBEsol0-3c, HSEsol-3c)

**Analytical first derivatives with respect to the nuclear coordinates and cell parameters**

- New Integral Engine for Faster Calculation of Analytical Energy Derivatives
- Hartree-Fock and Density Functional methods (LDA, GGA, mGGA, global- and range-separated hybrids)
- All-electron and Effective Core Potentials

**Analytical derivatives, up to fourth order, with respect to an applied electric field (CPHF/CPKS)**- Dielectric tensor, polarizability (linear-optical properties)
- First Hyper-polarizability (non linear-optical property)
- Second-Harmonic Generation
- Pockels Effect

- Second Hyper-polarizability (non linear-optical property)
- Extended to HJS-based some range-separated hybrid functionals (e.g. HSE06, HISS, LC-wPBE)

**Mixed analytical derivatives with respect to an applied electric field and either a nuclear displacement or a cell distortion (CPHF/CPKS)**- Born-charge tensor
- Raman polarizability tensors
- Direct Piezoelectric tensor (electronic term)

- Derivatives of the Electron Density, up to fourth order, for f- and g-type AOs

**One component single-point energy calculation**- Fock Matrix-mixing Scheme
- Broyden Convergence Accelerator
- Anderson Convergence Accelerator
- DIIS Convergence Accelerator
- Tools to define an Initial Guess for Magnetic Systems
- Fractionally-charged Systems
- Use of Fractional Spin
- Spin Contamination Correction

**Two component single-point energy calculation**- Self-consistent Treatment of Spin-Orbit Coupling (SOC)
- Non-Collinear Initial Guess for the Magnetization
- Fock Matrix-mixing Scheme

**Geometry optimizations**- Uses a quasi-Newton algorithm
- Extension of Model Initial Hessian to Lanthanides and Actinides
- Optimizes in symmetry-adapted cartesian coordinates
- Optimizes in redundant coordinates
- New internal coordinates handling and algorithm for back-transformation

- Full geometry optimization (cell parameters and atom coordinates)
- Freezes atoms during optimization
- Constant volume or pressure constrained geometry optimization (3D only)
- Transition state search

**Harmonic vibrational frequencies**- Harmonic vibrational frequencies at Gamma point
- Phonon dispersion using a direct approach (efficient supercell scheme)
- Phonon band structure and DOSs
- Calculation of Atomic Displacement Parameters and Debye-Waller factors
- IR intensities through localized Wannier functions and Berry Phase
- IR and Raman intensities through CPHF/CPKS analytical approach
- Simulated reflectance, IR and Raman spectra
- Vibrational contribution to dielectric tensor
- Vibrational contribution to first-hyper-polarizability
- Exploration of the energy and geometry along selected normal modes
- Total and Projected Vibrational Density-of-States (VDOS)
- Neutron-weighted VDOS for Inelastic Neutron Scattering
- Neutron-weighted VDOS for Inelastic Neutron Scattering - extended to heavy elements

**Anharmonic frequencies for X-H bonds**

**Anharmonic vibrational frequencies**- Development of the potential energy surface including up to fourth-order force constants
- Vibrational Self-Consistent Field (VSCF) and Vibrational Configuration Interaction (VCI) Treatments

**Automated calculation of the elastic tensor of crystalline systems**- Generalized to 2D and 1D systems
- Calculation of directional seismic wave velocities
- Calculation of isotropic polycrystalline aggregates elastic properties via Voigt-Reuss-Hill scheme
- Elastic Tensor under Pressure
- Complete Analysis of Elastic wave velocities through AWESOME Code
- Nuclear-relaxation Term through Internal-strain Tensor
- Thermo-Elasticity with quasi-static and quasi-harmonic schemes

**Automated E vs V calculation for equation of state (3D only)**- Murnaghan, Birch-Murnaghan, Vinet, Poirer-Tarantola and polynomial
- Automated calculation of pressure dependence of volume and bulk modulus

**Automated Quasi-harmonic Approximation (QHA) for Thermal Properties**- Volume-dependent Thermodynamic properties
- Lattice Thermal Expansion (anisotropic)
- P-V-T Equation-of-State
- Constant-pressure thermodynamic properties
- Temperature dependence of Bulk modulus (isothermal and adiabatic) - Gruneisen Parameters
- QHA generalized to 1D and 2D systems
- Thermo-Elasticity with quasi-static and quasi-harmonic schemes

**Automated calculation of piezoelectric and photoelastic tensors**- Direct and converse piezoelectricity (using the Berry phase approach)
- Elasto-optic tensor through the CPHF/CPKS scheme
- Electric field frequency dependence of photoelastic properties
- Nuclear-relaxation Term of Piezoelectric Tensor through Internal-strain Tensor
- Piezo-optic fourth-rank Tensor
- Analytical Piezoelectric Tensor through CPHF/KS Scheme

**Improved tools to model solid solutions**- Generation of configurations
- Automated algorithm for computing the energy (with or without geometry optimization) of selected configurations

**Gaussian type functions basis sets**- s, p, d, and f GTFs
- Extension of the LCAO Approach to g-type AOs
- Standard Pople Basis Sets
- STO-nG n=2-6 (H-Xe), 3-21G (H-Xe), 6-21G (H-Ar)
- polarization and diffuse function extensions

- Internal library of basis sets with simplified input
- Internal Libraries for POB-TZVP Consistent Basis Sets for Most Elements of the Periodic Table
- New Basis Sets for Lanthanides and Actinides with f Electrons in the valence
- User-defined External Library supported
- User-specified basis sets supported
- Internal Basis Set Optimizer
- Perturbation theory enrichment of the basis set

**Pseudopotential Basis Sets**- Internal libraries for AREP only
- Hay-Wadt large core
- Hay-Wadt small core
- Durand-Barthelat

- User-defined pseudopotential basis sets supported
- Internal libraries for AREP and SOREP
- Columbus large core
- Columbus small core
- Stuttgart-Cologne large core
- Stuttgart-Cologne small core

- Internal libraries for AREP only

**Periodicity**- Consistent treatment of all periodic systems
- 3D - Crystalline solids (230 space groups)
- 2D - Films and surfaces (80 layer groups)
- 1D - Polymers
- space group derived symmetry (75 rod groups)
- helical symmetry (up to order 48)

- 1D - Nanotubes (with any number of symmetry operators)
- 1D - Multi-wall Nanotubes
- 0D - Molecules (32 point groups)

**Automated geometry editing**- 3D to 2D - slab parallel to a selected crystalline face (hkl)
- 3D to 0D - cluster from a perfect crystal (H saturated)
- 3D to 0D - extraction of molecules from a molecular crystal
- 3D to n3D - supercell creation
- 2D to 1D - building single- and Multi-wall nanotubes from a single-layer slab model
- 2D to 0D - building fullerene-like structures from a single-layer slab model
- 3D to 1D, 0D - building nanorods and nanoparticles from a perfect crystal
- 2D to 0D - construction of Wulff's polyhedron from surface energies
- Several geometry manipulations (reduction of symmetry; insertion, displacement, substitution, deletion of atoms)

**Band structure**

**Density of states**- Band projected DOSS
- AO projected DOSS

**Crystal Orbital Overlap/Hamiltonian Populations**

**All Electron Charge Density - Spin Density**- Density maps
- Mulliken population analysis
- Density analytical derivatives
- Hirshfeld-I Partitioning Scheme
- Extended to f and g GTFs
- Extension of the TOPOND module for QTAIM to f and g AOs

**3D plotting of crystalline orbitals**

**Collinear and Non-collinear Magnetization density maps**

**Orbital-current density maps**

**Spin-current density maps**

**Electronic Transport Properties**- Boltzmann Transport Properties
- Electrical conductivity
- Seebeck coefficient
- Electronic part of the thermal conductivity

- Transport across Nanojunctions (interfaced to WanT)

- Boltzmann Transport Properties

**Atomic multipoles**

**Electric field**

**Electric field gradient**

**Static structure factors and dynamic structure factors including the Debye-Waller factor**

**Electron Momentum Density and Compton profiles**- Electron momentum density maps
- Automated anisotropy maps
- Partitioning according to Wannier functions

**Electrostatic potential and its derivatives**- Quantum and classical electrostatic potential and its derivatives
- Electrostatic potential maps

**Fermi contact**

**Localized Wannier Functions (Boys method)**

**Mossbauer effect (isotropic effect and quadrupolar interaction)**

**Dielectric properties**- Spontaneous polarization
- Berry Phase
- Localized Wannier Functions

- Dielectric constant through finite-field approximation

- Spontaneous polarization

**Topological analysis of the electron charge density via the TOPOND package, fully integrated in the program**- Generalized to f and g GTFs

**Memory management: dynamic allocation**

**Full parallelization of the code**- Parallel SCF and gradients for both HF and DFT methods
- Replicated data version (MPI)
- Parallel version of the "properties" module
- Parallelization strategy on IRREPs

- Massive parallel version (MPI) (distributed memory)
- OpenMP+MPI Hybrid Parallelism for SCF and Forces

**Enhanced exploitation of the point-group symmetry**

- Internal interface to TOPOND for topological analysis of the charge density
- External interface to WanT for calculation of transport properties across nanojunctions