Assessment of self-consistent field convergence in spin-dependent relativistic calculations

Highlights: • SCF acceleration techniques based on DIIS were implemented into the GHF framework. • Five convergence techniques were assessed for spin-dependent relativistic cases. • A combination of DIIS and EDIIS stably and efficiently converges GHF. This Letter assesses the self-consistent field (SCF) convergence behavior in the generalized Hartree–Fock (GHF) method. Four acceleration algorithms were implemented for efficient SCF convergence in the GHF method: the damping algorithm, the conventional direct inversion in the iterative subspace (DIIS), the energy-DIIS (EDIIS), and a combination of DIIS and EDIIS. Four different systems with varying complexity were used to investigate the SCF convergence using these algorithms, ranging from atomic systems to metal complexes. The numerical assessments demonstrated the effectiveness of a combination of DIIS and EDIIS for GHF calculations in comparison with the other discussed algorithms.