Co-iterative augmented Hessian method for orbital optimization

Understand

Orbital optimization procedure is widely called in electronic structure simulation.

• To efficiently find the orbital optimization solution, we developed a new second order orbital optimization algorithm, co-iteration augmented Hessian (CIAH) method.
• In this method, the orbital optimization is embedded in the diagonalization procedure for augmented Hessian (AH) eigenvalue equation.
• Approximations for Hessian matrix can be easily employed in this method to improve the computational costs.