Macs in Chemistry

Insanely Great Science

DIRAC10 Released

One of the advantages of the move to Mac OSX has been the increasing access to the heavy duty UNIX based computational chemistry programs.

One example is
DIRAC, a Program for Atomic and Molecular Direct Iterative Relativistic All-electron Calculations, the DIRAC program computes molecular properties using relativistic quantum chemical methods. Yesterday the release of DIRAC10 was announced with support for the following platforms Linux, AIX, Silicon Graphics, Apple under OS X (10.2 and higher), Sun Solaris, HP, Dec Alpha.

New features in DIRAC10 (released 10/10/10)
  • Methods:
    • Kramers-restricted MCSCF
    • RELADC for correlated calculations of single/double ionization spectra
    • large-scale parallel CI (LUCITA/KRCI)
    • intermediate Hamiltonian formalism for Fock-space CCSD
    • interface to MRCC (see http://tc03.fkt.bme.hu/)
    • frozen density embedding
  • Hamiltonians:
    • 2c X2C+AMFI for 2-electron spin-orbit corrections (spin-same orbit[SSO]/spin other-orbit[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:
    • visualization of unperturbed and perturbed densities
    • projection analysis of expectation values
    • expectation values/transition moments KRCI/GOSCI
Features in DIRAC08
  • Methods available:
    • Hartree-Fock
    • Density Functional Theory
    • Coupled Cluster
    • Configuration Interaction
    • Møller-Plesset Perturbation Theory
  • Hamiltonians available:
    • 4c Dirac-Coulomb (includes scalar relativistic effects and spin-own-orbit coupling)
    • 4c Dirac-Coulomb-Gaunt (includes also spin-other-orbit coupling) (only HF)
    • 4c spin-free Dirac-Coulomb (scalar relativistic effects only)
    • 4c Levy-Leblond (nonrelativistic)
    • 2c X2C, the one-step exact two-component Hamiltonian
    • 2c BSS, the two-step exact two-component Hamiltonian (= DKH(infinity,0))
  • Molecular properties:
    • Up to quadratic response properties at the Hartree-Fock 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 one-step exact two-component 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 non-relativistic 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
blog comments powered by Disqus