# Emanuel Rubensson

Senior Lecturer/Associate Professor at Department of Information Technology; Division of Scientific Computing

- Telephone:
- +46 18 471 29 81
- E-mail:
- emanuel.rubensson@it.uu.se
- Visiting address:
- Hus 10, Lägerhyddsvägen 1
- Postal address:
- Box 337

751 05 UPPSALA

- Academic merits:
- Docent, Excellent teacher

More information is available to staff who log in.

## Short presentation

My current research interests include theory and numerical methods for matrix functions and parallel programming models. I became interested in matrix functions when I was working on numerical methods used in computational chemistry, and some of my most important contributions are in this area. As a teacher, I have worked with feedback aimed at supporting self-regulated learning. I am currently the Head of the Division of Scientific Computing.

## Research

**Chunks and Tasks**, programming model, interface, and runtime libraries for parallelization of algorithms with dynamic work and data, see http://www.chunks-and-tasks.org.**Ergo**, algorithms, methods, and software for large-scale electronic structure calculations, see http://www.ergoscf.org.

## Publications

### Recent publications

- A unifying framework for higher order derivatives of matrix functions (2024)
- Quantum Perturbation Theory Using Tensor Cores and a Deep Neural Network (2022)
- The Chunks and Tasks Matrix Library (2022)
- Sparse approximate matrix-matrix multiplication for density matrix purification with error control (2021)
- Mixed Precision Fermi-Operator Expansion on Tensor Cores from a Machine Learning Perspective (2021)

### All publications

#### Articles

- A unifying framework for higher order derivatives of matrix functions (2024)
- Quantum Perturbation Theory Using Tensor Cores and a Deep Neural Network (2022)
- The Chunks and Tasks Matrix Library (2022)
- Sparse approximate matrix-matrix multiplication for density matrix purification with error control (2021)
- Mixed Precision Fermi-Operator Expansion on Tensor Cores from a Machine Learning Perspective (2021)
- Quantum-Based Molecular Dynamics Simulations Using Tensor Cores (2021)
- Localized inverse factorization (2021)
- A density matrix approach to the convergence of the self-consistent field iteration (2021)
- Parallelization and scalability analysis of inverse factorization using the chunks and tasks programming model (2019)
- Efficient computation of the density matrix with error control on distributed computer systems (2019)
- Linear scaling pseudo Fermi-operator expansion for fractional occupation (2019)
- On-the-fly computation of frontal orbitals in density matrix expansions (2018)
- Ergo (2018)
- Parameterless stopping criteria for recursive density matrix expansions (2016)
- Graph-based linear scaling electronic structure theory (2016)
- Locality-aware parallel block-sparse matrix–matrix multiplication using the Chunks and Tasks programming model (2016)
- Canonical density matrix perturbation theory (2015)
- Interior eigenvalues from density matrix expansions in quantum mechanical molecular dynamics (2014)
- Chunks and Tasks (2014)
- Comment on "On the optimal symmetric purification scheme of the one-particle density matrix" [Chem. Phys. Lett. 511 (2011) 159–160] (2012)
- Controlling errors in recursive Fermi–Dirac operator expansions with applications in electronic structure theory (2012)
- Nonmonotonic recursive polynomial expansions for linear scaling calculation of the density matrix (2011)
- Bringing about matrix sparsity in linear-scaling electronic structure calculations (2011)
- Assessment of density matrix methods for linear scaling electronic structure calculations (2011)
- Kohn–Sham density functional theory electronic structure calculations with linearly scaling computational time and memory usage (2011)
- Truncation of Small Matrix Elements Based on the Euclidean Norm for Blocked Data Structures (2009)
- Automatic Selection of Integral Thresholds by Extrapolation in Coulomb and Exchange Matrix Constructions (2009)
- Recursive inverse factorization (2008)
- Rotations of occupied invariant subspaces in self-consistent field calculations (2008)
- Density matrix purification with rigorous error control (2008)
- Computation of interior eigenvalues in electronic structure calculations facilitated by density matrix purification (2008)
- Hartree-Fock calculations with linearly scaling memory usage (2008)
- A hierarchic sparse matrix data structure for large-scale Hartree-Fock/Kohn-Sham calculations (2007)
- Determination of the chemical potential and HOMO/LUMO orbitals in density purification methods (2006)
- Systematic sparse matrix error control for linear scaling electronic structure calculations (2005)