The DIRAC code for relativistic molecular calculations
Trond Saue1, Radovan Bast2, André Severo Pereira Gomes3
1Laboratoire de Chimie et Physique Quantique, UMR 5626 CNRS-Université Toulouse III-Paul Sabatier, 118 Route de Narbonne, F-31062 Toulouse, France.
The Journal of Chemical Physics
|June 4, 2020
Summary
DIRAC is a versatile software for relativistic molecular calculations, offering advanced methods and user-defined property analysis. It incorporates environmental effects using sophisticated embedding models for comprehensive studies.
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Molecular Modeling
Background:
- Relativistic effects are crucial for accurate molecular calculations, especially for heavy elements.
- Existing computational chemistry software may lack comprehensive support for various relativistic theories and property calculations.
Purpose of the Study:
- To introduce DIRAC, a comprehensive software system for relativistic molecular calculations.
- To detail the implementation of advanced theoretical methods and user-defined property calculations within DIRAC.
- To present the integration of environmental effects through various embedding models.
Main Methods:
- Implementation of one-, two-, and four-component relativistic methods.
- Inclusion of Hartree-Fock, Kohn-Sham (including range-separated theory), multiconfigurational self-consistent-field, multireference configuration interaction, electron propagator, and coupled cluster theories.
- Development of a quaternion algebra-based scheme for symmetry treatment and a general module for molecular property calculations with visualization.
Main Results:
- DIRAC provides a flexible platform for a wide range of relativistic electronic structure calculations.
- The software enables user-defined molecular property calculations and analysis.
- Environmental effects can be incorporated using implicit solvation, explicit polarizable embedding, and frozen density embedding models.
Conclusions:
- DIRAC is a powerful and versatile tool for advanced relativistic molecular electronic structure studies.
- Its comprehensive methodology and user-friendly features facilitate complex chemical research.
- The integration of environmental effects enhances the applicability of DIRAC to condensed-phase and solvated systems.
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