29) Title: Introducing Asymmetric and Gradient Self-Consistent Field Methods To Optimize Single Determinant Wave Functions For Ground State Molecular Structure Calculations

Organizers: Sandor Kristyan, senior reserach advisor, Research Centre for Natural Sciences, (HUN-REN RCNS), H-1117 Budapest, Magyar Tudósok körútja 2, Hungary

Email: kristyan.sandor@ttk.mta.hu, kristyan.sandor@ttk.hu

We provide an algorithm for a high quality initial guess for linear combinations of atomic orbital (LCAO) coefficients to place the molecular system computationally into the convex neighborhood of the minimum of the Lagrangian to find the energy optimum in a simple novel self-consistent algorithm thereafter. In relation to algebra, the 4th order multi-variable polynomial in LCAO coefficients for ground state energy approximation is reduced to 3rd order; as a consequence, a 2nd order polynomial system has to be solved only for LCAO coefficients. We demonstrate it for the “restricted HF” case only, but the extension is straightforward.