features
Table of Contents
New features in DIRAC23
 Calculation of ParityViolating Nuclear SpinRotation Tensors. Activated with “.PVCSR”
 Contributor: I. Agustín Aucar.
 Reference: Ignacio Agustín Aucar and Anastasia Borschevsky, Relativistic study of parityviolating nuclear spinrotation tensors. J. Chem. Phys. 155, 134307 (2021) https://doi.org/10.1063/5.0065487
 Calculation of oscillator strengths beyond the electric dipole approximation in the generalized velocity representation
 Contributors: Martin van Horn, Trond Saue, and Nanna Holmgaard List.
 Reference: M. van Horn, T. Saue, N. H. List. Probing Chirality across the Electromagnetic Spectrum with the Full SemiClassical LightMatter Interaction. J. Chem. Phys. 156, 054113 (2022) https://doi.org/10.1063/5.0077502
 (e)amfX2C (improvement of AMFI): (extended) atomicmeanfield twoelectron scalar and spinorbit picturechange corrections for twocomponent Hamiltonian calculations
 Contributors: Stefan Knecht, Michal Repsiky, Hans Joergen Aa. Jensen and Trond Saue.
 Reference: Stefan Knecht, Michal Repisky, Hans Jørgen Aagaard Jensen, and Trond Saue, Exact twocomponent Hamiltonians for relativistic quantum chemistry: Twoelectron picturechange corrections made simple, J. Chem. Phys. 157, 114106 (2022) https://doi.org/10.1063/5.0095112
 ExaCorr module works now also with contracted basis functions.
 Contributor: Lucas Visscher.
 Basis set library has been extended with basis sets with diffuse functions for s and d blocks, dyall.aXNz basis sets. The Dyall basis sets can now be downloaded from the zenodo repository.
 Contributor: Ken Dyall.
Infrastructure changes
 HDF5 checkpoint file is now default for data handling
 Contributor: Lucas Visscher
 User manual: Data storage in DIRAC http://www.diracprogram.org/doc/release23/manual/data.html
 Developer manual: The CHECKPOINT.h5 file http://www.diracprogram.org/doc/release23/development/checkpoint.html
Revised features
 Added a CI gradient convergence threshold option '.THRGCI' to '\*KRCICALC' (could not be changed by user previously).
 Contributor: H. J. Aa. Jensen.
Performance improvements
 Improved code in luciarel CI program. Note that KRMC and KRCI by default uses luciarel.
 Contributor: Andreas Nyvang.
 numerical stability has been improved in the complex parallel diagonalization routine
 convergence algorithm has also been changed, with considerable improvement in convergence rate. In particular, the truncation of the reduced space in the Davidson iterations is now done in a much better way, leading to the improvement in convergence rate. Both for real and complex parallel cases.
Bugfixes
 Default for .MVO has been corrected, so it now behaves as expected: modified virtual orbitals based on the Fock potential from the doublyoccupied molecular orbitals after an openshell SCF calculation (H. J. Aa. Jensen).
New features in DIRAC22
 New licence : GNU Lesser General Public License v2.1only
 Electronic circular dichroism (ECD) beyond lowestorder – full lightmatter interaction. Contributors: Martin van Horn, Trond Saue and Nanna Holmgaard List
 Reference : M. van Horn, T. Saue, N. H. List. Probing Chirality across the Electromagnetic Spectrum with the Full Semiclassical LightMatter Interaction. J. Chem. Phys. (in press) (2022) ChemRxiv
 Manual:
 MP2 frozen virtual natural orbitals via the ExaCorr module.
 Contributors: Xiang Yuan, Lucas Visscher, André Severo Pereira Gomes.
 Reference: X. Yuan, L. Visscher, A. S. P. Gomes. Assessing MP2 frozen natural orbitals in relativistic correlated electronic structure calculations. arxiv.org/abs/2202.01146
 Polarizable Embedding with Complex Polarization Propagator.
 Contributors: Joel Creutzberg, Erik D. Hedegård
 Reference: Polarizable embedding complex polarization propagator in four and twocomponent frameworks. arXiv:2112.07721
 Manual: *PEQM and tutorial PETDDFT calculations of excitation energies and solvent shifts¶
Infrastructure changes and fixes
 HDF5 checkpoint file and DIRAC data scheme, python utilities to extract data.
 Contributor: Lucas Visscher
 Manual: The CHECKPOINT.h5 file
Revised features in DIRAC22
Improvements
 DIIS replaced by CROP algorithm in ExaCorr module. Contributors: Chima Chibueze and Lucas Visscher.
 Reference ExaCorr: J.V. Pototschnig et al., J. Chem. Theory Comput. 17 (2021) 5509−5529.
 Manual: EXACC
New features in DIRAC21
 Molecular rotational gtensors. Contributor: I. Agustín Aucar.
 Reference: I. A. Aucar, S. S. Gómez, C. G. Giribet and M. C. Ruiz de Azúa. Theoretical study of the relativistic molecular rotational gtensor.J. Chem. Phys. 141 (2014) 194103
 Manual: ".ROTG"
 Tutorial: Molecular rotational gtensors
 ExaCorr GPUaware parallel coupled cluster module. Contributors: Johann V. Pototschnig, Anastasios Papadopoulos, Dmitry I. Lyakh, Michal Repisky, Loïc Halbert, André Severo Pereira Gomes, Hans Jørgen Aa. Jensen, Lucas Visscher.
 Reference: J. V. Pototschnig, A. Papadopoulos, D. I. Lyakh, M. Repisky, L. Halbert, A. S. P. Gomes, H. J. Aa. Jensen, L. Visscher. Implementation of relativistic coupled cluster theory for massively parallel GPUaccelerated computing architectures. arXiv:2103.08473 [physics.chemph]
 Manual: "**EXACC"
 Atomic supersymmetry. Contributors: A. Sunaga and T. Saue
 Manual: ".KPSELE"
 Tutorial: Converging atoms
 Beyond the electricdipole approximation When calculating excitation energies at the HartreeFock or KohnSham levels, intensities can be calculated using the full semiclassical lightmatter interaction as well as truncated interaction to arbitrary order in the wave vector in both the length and velocity representation. Rotational average is provided by default, but specific orientations can also be chosen. Contributors: Nanna H. List and Trond Saue
 Reference: Nanna Holmgaard List, Timothé Romain Léo Melin, Martin van Horn and Trond Saue: Beyond the electricdipole approximation in simulations of Xray absorption spectroscopy: Lessons from relativistic theory, J. Chem. Phys. 152 (2020) 184110
 Manual: ".BED"
 Tutorial: coming soon
Revised features in DIRAC21
 Gauge origin, dipole origin, and phase origin (.GAUGEO alias .GO ANG, .DIPORG, and .PHASEO, respectively) can now ONLY be set under **HAMILTONIAN.
New Interfaces
 Interface to ROSE (Localized Orbitals). Main contributor: Bruno Senjean.
 Reference: B. Senjean, S. Sen, M. Repisky, G. Knizia, L. Visscher. Generalization of Intrinsic Orbitals to KramersPaired Quaternion Spinors, Molecular Fragments, and Valence Virtual Spinors. J. Chem. Theory Comput. 17 (2021) 1337–1354
 ROSE repository (including documentation): gitlab.com/quantum_rose
 Extract DIRAC data to Python (see utils/dirac_data.py). Contributor: L. Visscher.
Improvements
 Significantly improved performance of GASCIP configuration interaction module. Contributor: Hans Jørgen Aa. Jensen
Change of defaults
 The format of the DFCOEF coefficient file has changed. You can convert oldstyle files to the new format using the utility routine cf_addlabels.x found in the the build directory after make.
 The CODATA2018 set of physical constants is now used as default. Values are taken from NIST web page (http://physics.nist.gov/constants). Before DIRAC21, values from CODATA1998 were default. New keyword was implemented to select the desired set of data. Contributor: Agustín Aucar
 Manual: ".CODATA"
 In the compilation step OpenMP is now enabled by default.
 Oneelectron operator ANGMOM's origin was moved from gaugeorigin to the molecular center of mass.
Known issues
 Atomic supersymmetry does not work in combination with the molecularmeanfield X2C approach.
 ExaTensor (ExaCorr module) doesn't raise an error if it runs out of memory, but hangs
New features in DIRAC19
 EOMCC  core excitation and ionization energies via corevalence separation using projectors in RELCC (Avijit Shee, Andre Gomes, Marta Lopez Vidal)
 Reference: L. Halbert, M. L. Vidal, A. Shee, S. Coriani, A. S. P. Gomes Relativistic EOMCCSD for CoreExcited and CoreIonized State Energies Based on the FourComponent Dirac–Coulomb(−Gaunt) HamiltonianJ. Chem. Theory Comput. 17 (2021), 3583
 Manual: see keywords under "*CCPROJ"
 Python interface of DIRAC with Openfermion (Bruno Senjean) to perform relativistic quantum chemistry calculations simulated on a quantum computer .
 Nuclear SpinRotation tensors. Contributors: I. Agustin Aucar and Trond Saue.
 Reference: I. A. Aucar, S. S. Gómez, M. C. Ruiz de Azúa, and C. G. Giribet. Theoretical study of the nuclear spinmolecular rotation coupling for relativistic electrons and nonrelativistic nuclei.J. Chem. Phys. 136 (2012) 204119
 Manual: ".SPINR"
 Tutorial: Nuclear spinrotation constants
 Nuclear MagneticQuadrupoleMoment interaction constant in KRCI (Malaya K. Nayak)
 Reference: T. Fleig, M. K. Nayak and M. G. Kozlov TaN, a molecular system for probing P,Tviolating hadron physics.Phys. Rev. A 93 (2016) 012505
Improvements
 Improved root tracking for EOMCC (Luuk)
 Use Kramers conjugation on doubly degenerate CI vectors in GASCIP code (cuts time for CI in half for ESR doublets) (Hans Jørgen)
Bugfixes
 DFT magnetizatibilities with LAOS and symmetry (Gosia Oejniczak and Trond Saue)
 Resolved runtime issues in KRCI property modules (Malaya K. Nayak)
Change of defaults
 Upgrade to python3
New features in DIRAC18
 DFT magnetizabilities. Contributors: M. Olejniczak and Trond Saue.
 Limitations: Magnetizabilities and NMR shieldings calculated at the DFT level are so far restricted to C1 symmetry, but we expect to fix this soon.
 Enhancements to the frozen density embedding (FDE) functionality
 FDE contributions to magnetic properties (NMR shieldings, indirect spinspin coupling constants, magnetizabilities), see ".FDE" and "*FDE" entries of the manual for details. Contributors: M. Olejniczak, R. Bast, A. S. P. Gomes
 References:
 M. Olejniczak, R. Bast, A. S. P. Gomes On the calculation of secondorder magnetic properties using subsystem approaches in a relativistic framework. Phys. Chem. Chem. Phys. 19 (2017) 8400
 Tutorials:
 FDE interaction energies with CCSD, MP2 and meanfield densities. Contributors: M. Olejniczak, A. Shee, R. Bast, A. S. P. Gomes
 Equation of motion coupled cluster
 Energies for electronic excitations (EE), electron attachment (EA) and electron detachment (IP), see ".EOMCC", "*EOMCC" and "*CCDIAG" entries of the manual for details. Contributiors: A. Shee, T. Saue, L. Visscher, A. S. P. Gomes
 References:
 A. Shee, T. Saue, L. Visscher, A. S. P. Gomes Equationofmotion coupledcluster theory based on the 4component DiracCoulomb(Gaunt) Hamiltonian. Energies for single electron detachment, attachment, and electronically excited states. J. Chem. Phys. 149 (2018) 174113
Improvements
 Polarized embedding can be done with xyzfiles. Contributor: Trond Saue
 Improved quaternion diagonalization Contributor: H. J. Aa. Jensen
 Improvements in the visualization module (**VISUAL) Contributors: M. Olejniczak and T. Saue.
 the possibility to calculate the NMR shielding tensor in a selected point in space, see ".NICS"
 the possibility to visualize various densities on an imported 3D grid, see ".3D_IMP"
 the possibility to calculate magnetic properties densities using the imported magneticallyinduced current density, see ".READJB"
 the possibility to scale densities by Cartesian products x^{i}y^{j}z^{k}, see ".CARPOW"
 the possibility to generate and visualize radial distributions, see ".RADIAL"
Change of defaults
 New convergence criterium for CC amplitude equation: The convergence criterium for the amplitude equations that determine the CC energy has been revised and made consistent with the criterium used in the lambda equations used for molecular properties. In both cases we now take the norm of the differences between amplitudes of subsequent iterations. In practice this typically means the program will use a few iterations less. For normal calculations this is of no consequence as the default is still to converge very tightly, but if extremely high precision is required one may need to check the achieved convergence.
 Change in the reorthonormalization terms in the calculation of magnetic properties with London atomic orbitals: the reorthonormalization and response contributions involve the same orbital pairs, for instance if all rotations between occupied and virtual orbitals are present in response equations, the reorthonormalization terms are also constructed from all orbital blocks; the keywords .DOEPRN and .NOEPRN under *NMR are depreciated;
New features in DIRAC17
 Kramersrestricted Polarization Propagator in the ADC framework for electronic excitations, activated with ”.POLPRP”.
 References:
 M. Pernpointner. The relativistic polarization propagator for the calculation of electronic excitations in heavy systems. J. Chem. Phys. 140, 084108 (2014)
 M. Pernpointner, L. Visscher and A. B. Trofimov. Fourcomponent Polarization Propagator Calculations of Electron Excitations: Spectroscopic Implications of SpinOrbit Coupling Effects. J. Chem. Theory Comput. 14, 1510 (2017).
 Tutorials:
 New expectation values in the KRCI module:

 Reference: T. Fleig and M. K. Nayak. Electron electric dipole moment and hyperfine interaction constants for ThO. J. Mol. Spectrosc., 300:16, 2014

 Reference: see T. Fleig and M. K. Nayak. Electron electricdipolemoment interaction constant for HfF^{+} from relativistic correlated allelectron theory. Phys. Rev. A, 88:032514, 2013

 Reference: M. Denis, M. Nørby, H. J. Aa . Jensen, A. S. P. Gomes, M. K. Nayak, S. Knecht, and T. Fleig. Theoretical study on ThF^{+}, a prospective system in search of timereversal violation. New J. Phys., 17:043005, 2015

 Polarizable embedding using pelib.
 Reference: E. D. Hedegård, R. Bast, J. Kongsted, J. M. H. Olsen, and H. J. Aa. Jensen. Relativistic Polarizable Embedding. J. Chem. Theory Comput. 13, 28702880 (2017)
 Tutorials:
 New ”.MVOFAC” option in *KRMC input section for Modified Virtual Orbitals in MCSCF. Contributor: H. J. Aa. Jensen.
 New and numerically stable procedure for elimination/freezing of orbitals at SCF level. Contributor: T. Saue.
 New easier options for point charges in the .mol file: “LARGE POINTCHARGE” or “LARGE NOBASIS” (the two choices are equivalent), see here
 Provided memory counter for RelCC calculations, suitable for memory consuming large scale Coupled Cluster calculations, see here for details. Contributor: Miroslav Iliaš
 Write out effective Hamiltonian in Fock space coupled cluster to a file for post processing. Can be used with external code of Andrei Zaitsevskii (St. Petersburg).
 Restart for RELCCSD. Contributor: Andre Gomes. See the keyword .RESTART and the section *CCRESTART
Performance Improvements
 Restored integral screening. Contributor: Hans Jørgen Aagaard Jensen
 POLPRP module + Davidson diagonalizer now parallel. Contributor: Markus Pernpointner
Corrections
 Fixed errors for quaternion symmetries in 2electron MO integrals used in CI calculations with GASCIP. It is now possible to do CI calculations with GASCIP for C1 symmetry (i.e. no symmetry).
 Fixed error for parallel complex CI or MCSCF with GASCIP
 Fixed compilation of XCFun on Mac OS X High Sierra.
Change of defaults
 Change of final (open shell) orbital energies + SCF cycle modification. Contributors: Hans Jørgen Aagaard Jensen and Trond Saue
 .SKIPEP is now default for KRMCSCF, new keyword .WITHEP to include ep rotations
Basis set news
 Added the RPF4Z and augRPF4Z basis sets for felements to the already existing files with sets for s, p and d elements. Deleted the augRPF3Z set as that was not an official set.
 Fixed the p exponents for Na in the dyall 4z basis sets to match the archive. The changes are small so should not significantly affect results.
 Updated basis_dalton/ with basis set updates in the Dalton distribution:
 fix of errors in AhlrichspVDZ (several diffuse exponents were a factor 10 too big)
 fix of errors for 2. row atoms in augccpCV5Z
 added many atoms to augccPVTZ_J
 added many Frank Jensen “pc” type basis sets
 added Turbomole “def2” type basis sets
New features in DIRAC16
 RELCCSD expectation values. For more information, see J. Chem. Phys. 145 (2016) 184107 as well as test/cc_gradient for an example.
 Improved start potential for SCF: sum of atomic LDA potentials, generated by GRASP.
Change of defaults
 Negative denominators (e.g. appearing in core ionized systems) accepted in RELCCSD
 AOFOCK is now default if at least 25 MPI nodes (parallelizes better than SOFOCK). And .AOFOCK documented.
Corrections
 Error corrections and updates in isotope properties for the following atoms:
 Br isotope 2: quadrupole moment .2620 → .2615
 Ag isotope 2: magnetic moment .130563 → .130691 (note sign change)
 In isotope 2: quadrupole moment .790 → .799
 Nd magnetic moments of isotopes 4 and 5 were interchanged: 0.065 → 1.065 and 1.065 → 0.065
 Gd: quadrupole moments of isotopes 4 and 5 updated: 1.36 → 1.35 and 1.30 → 1.27
 Ho isotope 1: quadrupole moment updated 3.49 → 3.58
 Lu isotope 2: quadrupole moment updtaed 4.92 → 4.97
 Hf isotope 1: mass was real*4, not real*8, thus 7 digits instead of 179.9465457D0 (i.e. approx 179.9465)
 Ta isotope 1: quadrupole moment added 0.00 → 3,17
 Tl isotope 1: nuclear moment 1.63831461D0 → 1.63821461D0 (typo, error 1.d4)
 Pb isotope 3: nuclear moment 0.582583D0 → 0.592583D0 (typo, error 1.d2)
 Po isotope 1: nuclear moment added: 0.000 → 0.688
 For other bug fixes compared to DIRAC15 we refer to CHANGELOG.rst in the main directory of the Dirac distribution.
New features in DIRAC15
 FanoADCStieltjes: Calculation of decay widths of electronic decay processes. For more information see JCP 142, 144106 (2015).
 DIRRCI expectation values, see test/dirrci_property for an example.
 Geometry optimization with xyz input, see test/geo_opt_xyz for an example
 KRMCSCF: Performance improvements for determinant generation in GASCIP
Basis set news
 Relativistic prolapsefree Gaussian basis sets of quadruplezeta quality: RPF4Z, augRPF4Z
 s and pblock elements: T. Q. Teodoro, A. B. F. da Silva, and R. L. A. Haiduke, J. Chem. Theory Comput. 10 (2014) 3800
 dblock elements: T. Q. Teodoro, A. B. F. da Silva, and R. L. A. Haiduke, J. Chem. Theory Comput. 10 (2014) 4761
 ANORCC basis:
 Fixed Carbon basis set (wrong contraction coefficients, see [MOLCAS ANORCC](http://www.molcas.org/ANO/).
 Modified the 3 Th hfunctions by replacing them with the 3 Ac hfunctions to Th.
 Fixed reading of ANORCC and ANODK3 basis sets from the included basis set library.
New defaults
 For openshell SCF calculations, .OPENFAC = 0.5 by default, as this seems to improve convergence. Final orbital energies are recalculated with .OPENFAC 1.0, for IP interpretation.
Improved compilation and testing
 Configuration framework uses [Autocmake](http://autocmake.org).
New features in DIRAC14
 Intrinsic Atomic Orbitals (IAOs), as formulated by Gerald Knizia, have been implemented to eliminate the polarization contribution in projection analysis.
 The Polarizable Continuum Model (PCM) is available for the inclusion of solvent effects. For more details, see this paper
 As a byproduct of the PCM implementation, molecular electrostatic potential (MEP) maps are available for 4component electronicstructure calculations, see this paper
 +Q corrections (sizeconsistency corrections) for KRCI calculations
 Extended Hückel method using atomic fragments for SCF start guess (alternative to atomic start)
New features in DIRAC13
 Improved output for TDDFT excitation energies (from patch 13.1)
 XML output functionality
 Enhancements to frozen density embedding
 Polarization propagator for 4C excitations (ADC2 extended)
 Enhancements to X2C: local spinfree and spinorbit X2C
 Dyall basis sets redefined to reduce linear dependence and conform to basis archive files, including fixes
 Basis sets for 1s, 2s, 2p, 3s, 3p, 3d added to Dyall 2z, Dyall 3z and Dyall 4z sets
 Polarized basis sets for SCF/DFT calculations: Dyall 2zp, 3zp, and 4zp, covering valence and outer core polarization
 Dyall aenz (allelectron) basis sets added, with correlating functions for all shells
Improved compilation and testing
 Support for Windows 7/8 with GNU MinGW32/64 suite and native math libraries
 New test script
 Simplified testing using MPI
 Updated math library detection
 Better support for MKL libraries
 Support for Cray
 Support for MPI runs which do not use mpirun
New defaults
 The pam script sets (unless these variables are set by the user):
MKL_NUM_THREADS=1 MKL_DYNAMIC="FALSE" OMP_NUM_THREADS=1 OMP_DYNAMIC="FALSE"
New features in DIRAC12 (released 12/12/12)
 London Atomic Orbitals (LAOs) at the DFT level
 Simple magnetic balance for NMR shieldings
 LAO current densities
 Overlap diagnostic for TDDFT calculations of excitation energies
 PipekMezey localization by trustregion optimization
 Atomic start guess for SCF calculations
 Complex/Damped DFT response module
 New Lanczos algorithm for relativistic Algebraic Diagrammatic Construction (ADC)
New defaults
 New input style for RELCC and RELADC
 Changed level shift
 Changed bare nucleus corrections (new parameters)
 New MPI 64/32interface
 Improved start guess and improved SCF convergence
New features in DIRAC11 (released 11/11/11)
 Analytic molecular gradient at the DFT level
 New and fast XC integration
 Functional derivatives using automatic differentiation (XCFun)
 New visualization options
 RKBIMP: MOcoefficients generated using restricted kinetic balance (RKB) can be extended by their unrestricted kinetic balance (UKB) complement, thus providing magnetic balance for response calculations involving external magnetic fields
 New and improved 2c Hamiltonian schemes
New build system and infrastructure
 New compilation scheme: configure replaced by CMake mechanism
 New pam script (python)
 Alternative launcher: wrapper.py (python)
 New testing framework based on python (runscript)
 Many static allocation calls replaced by dynamic allocation; in practice this means that you may need less WORK array memory and/or more space for dynamic allocation compared to DIRAC10.
New mailing list
Important input changes
 XC GRID has own input section
 .DHF is now .SCF
Changed defaults
 .LVCORR is now default; you can force explicit evaluation of (SSSS) integrals with .DOSSSS
Methods
 HartreeFock
 Density Functional Theory
 Kramersrestricted MultiConfiguration SelfConsistentField
 Coupled Cluster
 Configuration Interaction
 MoellerPlesset Perturbation Theory
Hamiltonians
 4c DiracCoulomb (includes scalar relativistic effects and spinownorbit coupling)
 4c DiracCoulombGaunt (only HF; includes also spinotherorbit coupling)
 4c spinfree DiracCoulomb (scalar relativistic effects only)
 4c LevyLeblond (nonrelativistic)
 2c X2C, the onestep exact twocomponent Hamiltonian
 2c BSS, the twostep exact twocomponent Hamiltonian (= DKH(infinity,0))
 2c molecularmeanfield (= X2Cmmf), X2C transformation with the converged 4cFock operator as defining Hamiltonian
Molecular properties
 Up to quadratic response properties at the HF and DFT level
 Firstorder properties with MP2
 Core excitation energies in the static exchange (STEX) approximation
 Ionization energies at the ADC(3) level of theory
 Selected firstorder properties with CI
Efficiency
 Full symmetry handling for linear molecules (otherwise up to D2h)
 Parallelization using MPI library calls (MPI should be preinstalled)
New features in DIRAC10 (released 10/10/10)
Methods
 Kramersrestricted MCSCF
 RELADC for correlated calculations of single/double ionization spectra
 largescale parallel CI (LUCITA/KRCI)
 intermediate Hamiltonian formalism for Fockspace CCSD
 interface to MRCC
 frozen density embedding
Hamiltonians
 2c X2C+AMFI for 2electron spinorbit corrections (spinsame orbit[SSO]/spin otherorbit[SOO])
Molecular properties
 HF/KS excitation energies
 KS response with noncollinear spin polarization and full derivative of functionals
 linear response functions at imaginary frequencies
 more efficient KS DFT code
 London orbitals for HF NMR shieldings
Analysis tools
 visualization of unperturbed and perturbed densities
 projection analysis of expectation values
 expectation values/transition moments KRCI/GOSCI
Features in DIRAC08
Methods
 HartreeFock
 Density Functional Theory
 Coupled Cluster
 Configuration Interaction
 Second order MollerPlesset Perturbation Theory
Hamiltonians
 4c DiracCoulomb (includes scalar relativistic effects and spinownorbit coupling)
 4c DiracCoulombGaunt (includes also spinotherorbit coupling) (only HF)
 4c spinfree DiracCoulomb (scalar relativistic effects only)
 4c LevyLeblond (nonrelativistic)
 2c X2C, the onestep exact twocomponent Hamiltonian
 2c BSS, the twostep exact twocomponent Hamiltonian (= DKH(infinity,0))
Molecular properties
 Up to quadratic response properties at the HartreeFock and DFT level
 First order properties with MP2
 Core excitation energies in the static exchange (STEX) approximation.
 Single/Double Ionization energies and spectra at the ADC(3)/ADC(2x) level of theory.
Efficiency
 Full symmetry handling for linear molecules (otherwise up to D2h)
 Parallelization using MPI library calls (MPI should be preinstalled)
Some of the new features of DIRAC08
 A onestep exact twocomponent Hamiltonian (X2C)
 Relativistic Green's function (propagator) module RELADC for the calculation of ionization energies
 Possibility to include the Gaunt interaction in HF calculations
 Implementation of several new density functionals
 Linear and quadratic response DFT
 Addition of the latest Dyall basis sets and more nonrelativistic basis sets to the basis library
 Analysis by means of fragment orbitals
 New parallelization of the MOLTRA module with reduced I/O
 Parallelization of the LUCITA CI module
features.txt · Last modified: 2023/02/21 15:48 by tsaue