Programme

I.9 -- Invited, VCTP-48

Date: Thursday, 3 August 2023

Time: 14:00 - 14:40

Development of correlated mean-field theory beyond density functional theory

Lan Nguyen Tran

International University, Vietnam National University – Ho Chi Minh City

I will present our development of a correlated mean-field theory: OBMP2. In our method, an effective Hamiltonian is derived using canonical transformation. Cumulant approximation is then used to reduce the many-body operators into one-body operators. The effective one-body Hamiltonian is diagonalized to update orbitals and orbital energies, resulting in a self-consistency. We have tested our method for molecular systems and found that our method outperforms widely used methods like density functional theory (DFT) and many-body perturbation theories. We also combine our method with a current state-of-the-art quantum computing algorithm, VQE, to simulate challenging molecules. We are also extending our method for materials.     [1] Nhan Trong Le, Lan Nguyen Tran, “Correlated reference-assisted variational quantum eigensolver”, J Phys Chem A, 2023 accepted. [2] Lan Nguyen Tran, “Can second-order perturbation theory accurately predict electron density of open-shell molecules? The importance of self-consistency”, Phys Chem Chem Phys 24 19393, 2022 [3] Lan Nguyen Tran, “Improving perturbation theory for open-shell molecules via self-consistency”, J Phys Chem A 125 9242, 2021.

Presenter: Tran Nguyen Lan