Comparison of self-consistent field convergence acceleration techniques.

Area of Science:

• Computational chemistry
• Quantum chemistry
• Electronic structure theory

Background:

• Accelerating self-consistent field (SCF) convergence is crucial for computational chemistry.
• Several methods, including ADIIS, LIST, and energy-DIIS (EDIIS) + DIIS, have been proposed to improve SCF convergence rates.
• Previous studies have reported varying degrees of success and limitations for these methods.

Purpose of the Study:

• To mathematically compare the recently proposed ADIIS and LIST methods with the established EDIIS + DIIS technique for SCF convergence acceleration.
• To investigate and clarify reported convergence failures of the EDIIS + DIIS method.
• To determine the most effective DIIS-based method for SCF convergence.

Main Methods:

• Mathematical derivation to demonstrate the identity between ADIIS and EDIIS for Hartree-Fock wavefunctions.
• Implementation and testing of ADIIS, LIST, and EDIIS + DIIS methods using computational codes.
• Comparative analysis of convergence performance across different methods and computational cases.

Main Results:

• ADIIS functional is mathematically identical to EDIIS for Hartree-Fock wavefunctions.
• Reported convergence failures of EDIIS + DIIS were not reproduced with the current codes, suggesting implementation-dependent issues.
• Correctly implemented EDIIS + DIIS generally outperformed LIST methods in tested cases.

Conclusions:

• EDIIS + DIIS remains the preferred method for SCF convergence acceleration within the DIIS family.
• The findings highlight the importance of correct implementation for achieving optimal performance of SCF convergence algorithms.
• Further investigation into the nuances of different DIIS methods may be warranted for specific computational challenges.