48 citations · 145 across the 9 of their papers we have counts for
9 papers
Extending orbital-optimized density functional theory to L-edge XPS and beyond: Spin-orbit coupling via non-orthogonal quasi-degenerate perturbation theory
Richard Kang, Leonardo A. Cunha, Diptarka Hait +1
Quantum mechanical calculations of core electron binding energies (CEBEs) leading to 2p hole states are relevant to interpreting L-edge x-ray photo-electron spectroscopy (XPS), as…
Photon Many-body Dispersion: an Exchange-correlation Functional for Strongly Coupled Light-matter Systems
Cankut Tasci, Leonardo A. Cunha, Johannes Flick
We introduce an electron-photon exchange-correlation functional for quantum electrodynamical density-functional theory (QEDFT). The approach, photon MBD (pMBD), is inspired by the…
Only Tails Matter: Average-Case Universality and Robustness in the Convex Regime
Leonardo Cunha, Gauthier Gidel, Fabian Pedregosa +2
The recently developed average-case analysis of optimization methods allows a more fine-grained and representative convergence analysis than usual worst-case results. In exchange,…
Electron-Affinity Time-Dependent Density Functional Theory: Formalism and Applications to Core-Excited States
Kevin Carter-Fenk, Leonardo A. Cunha, Juan E. Arias-Martinez +1
The particle-hole interaction problem is longstanding within time-dependent density functional theory (TDDFT) and leads to extreme errors in the prediction of K-edge X-ray absorpti…
Accurate core excitation and ionization energies from a state-specific coupled-cluster singles and doubles approach
Juan E. Arias-Martinez, Leonardo A. Cunha, Katherine J. Oosterbaan +2
We investigate the use of orbital-optimized references in conjunction with single-reference coupled-cluster theory with single and double substitutions (CCSD) for the study of core…
Changes in polarization dictate necessary approximations for modeling electronic de-excitation intensity: an application to X-ray emission
Subhayan Roychoudhury, Leonardo A. Cunha, Martin Head-Gordon +1
We systematically investigate the underlying relations among different levels of approximation for simulating electronic de-excitations, with a focus on modeling X-ray emission spe…
Relativistic Orbital Optimized Density Functional Theory for Accurate Core-Level Spectroscopy
Leonardo A. Cunha, Diptarka Hait, Richard Kang +2
Core-level spectra of 1s electrons of elements heavier than Ne show significant relativistic effects. We combine advances in orbital optimized DFT (OO-DFT) with the spin-free exact…
Approaching the Basis Set Limit in Gaussian-Orbital-Based Periodic Calculations with Transferability: Performance of Pure Density Functionals for Simple Semiconductors
Joonho Lee, Xintian Feng, Leonardo A. Cunha +3
Simulating solids with quantum chemistry methods and Gaussian-type orbitals (GTOs) has been gaining popularity. Nonetheless, there are few systematic studies that assess the basis…
Exploring Spin Symmetry-Breaking Effects for Static Field Ionization of Atoms: Is There an Analog to the Coulson-Fischer Point in Bond Dissociation?
Leonardo A. Cunha, Joonho Lee, Diptarka Hait +2
Löwdin's symmetry dilemma is an ubiquitous issue in approximate quantum chemistry. In the context of Hartree-Fock (HF) theory, the use of Slater determinants with some imposed cons…