139 citations · 341 across the 23 of their papers we have counts for
25 papers
Ab Initio Approach for Quantum Magnets with Coupled Cluster and Transcorrelation
Kristoffer Simula, Nikolay A. Bogdanov, Olle Gunnarsson +2
The nearest-neighbour exchange coupling is the simplest ingredient of model Hamiltonians used to understand magnetism in real materials. Nevertheless, its ab initio determina…
First application of the transcorrelated method to noncovalent interactions: The A24 dataset
Johannes Hauskrecht, Stephanie Lambie, Evelin Martine Corvid Christlmaier +3
We present the first application of transcorrelated (TC) coupled-cluster (CC) theory to noncovalent interactions within the xTC approximation. The method is assessed for the A24 da…
ElemCo.jl: A Julia package for electron-correlation methods
Daniel Kats, Charlotte Rickert, Thomas Schraivogel +3
We present ElemCo.jl, an open-source Julia package for molecular electronic structure and properties calculations with a particular emphasis on Coupled Cluster and Distinguishable…
Orbital-Optimized Quasi-Variational Distinguishable Cluster Doubles Method
Fangcheng Wu, Daniel Kats
We present the orbital-optimized quasi-variational distinguishable cluster doubles (OQVDCD) method, obtained by applying the distinguishable cluster (DC) approximation to orbital-o…
Compression of virtual spaces in transcorrelated methods via singular value decomposition: application to the G2 set
Yifan Cheng, Kristoffer Simula, Johannes Hauskrecht +3
We introduce a new singular-value-decomposition-based scheme for constructing small virtual spaces out of large basis sets for transcorrelated (TC) calculations, termed SVD-TC. Thi…
An Additive Reference Correction Scheme for the Transcorrelated Method
Johannes Hauskrecht, Kristoffer Simula, Yifan Cheng +3
We introduce an additive reference correction for the transcorrelated (TC) method and its three-body mean-field approximation (xTC), to improve energy differences computed in small…
Application of the aperiodic defect model to a negatively charged monovacancy in phosphorene
Charlotte Rickert, Lily Barta, Ernst-Christian Flach +2
We apply the recently introduced aperiodic defect model (ADM) to a negatively charged monovacancy in a phosphorene monolayer. In contrast to conventional supercell approaches, the…
A Transcorrelated Wave-Function Framework for Solids: An Application to Bulk and Defected Silicon
Kristoffer Simula, Johannes Hauskrecht, Evelin Martine Corvid Christlmaier +4
Accurate wave-function descriptions of pristine and defected solids remain challenging due to the simultaneous presence of finite-size, basis-set, and correlation errors. While emb…
Deterministic Optimisation of Jastrow Factors
Maria-Andreea Filip, Evelin M. C. Christlmaier, J. Philip Haupt +3
Highly flexible Jastrow factors have found significant use in stochastic electronic structure methods such as variational Monte Carlo (VMC) and diffusion Monte Carlo, as well as in…
Transcorrelated Methods for Multireference Problems
J. Philip Haupt, Evelin M. C. Christlmaier, Pablo López Ríos +3
We apply the transcorrelated method to problems of multireference character. For this, we show that the choice of reference wavefunction during the Jastrow optimisation procedure i…
Transcorrelated Theory with Pseudopotentials
Kristoffer Simula, Evelin Martine Corvid Christlmaier, Maria-Andreea Filip +4
The transcorrelated (TC) method performs a similarity transformation on the electronic Schrödinger equation via Jastrow factorization of the wave function. This has demonstrated si…
On the applicability of CCSD(T) for dispersion interactions in large conjugated systems
S. Lambie, D. Kats, D. Usyvat +1
In light of the recent discrepancies reported between fixed node diffusion Monte Carlo and local natural orbital coupled cluster with single, double and perturbative triples (CCSD(…
Transcorrelated Methods Applied to Second Row Elements
Maria-Andreea Filip, Pablo López Ríos, J. Philip Haupt +3
We explore the applicability of the transcorrelated method to the elements in the second row of the periodic table. We use transcorrelated Hamiltonians in conjunction with full con…
Tensor Decomposed Distinguishable Cluster. I. Triples Decomposition
Charlotte Rickert, Denis Usvyat, Daniel Kats
We present a cost-reduced approach for the distinguishable cluster approximation to coupled cluster with singles, doubles and iterative triples (DC-CCSDT) based on a tensor decompo…
Aperiodic defects in periodic solids
Robert H. Lavroff, Daniel Kats, Lorenzo Maschio +4
To date, computational methods for modeling defects (vacancies, adsorbates, etc.) rely on periodic supercells in which the defect is far enough from its repeated image such that th…
Orbital optimisation in xTC transcorrelated methods
Daniel Kats, Evelin M. C. Christlmaier, Thomas Schraivogel +1
We present a combination of the bi-orthogonal orbital optimisation framework with the recently introduced xTC version of transcorrelation. This allows us to implement non-iterative…
Two Determinant Distinguishable Cluster
Thomas Schraivogel, Daniel Kats
A two reference determinant version of the distinguishable cluster with singles and doubles (DCSD) has been developed. We have implemented the two determinant distinguishable clust…
xTC: An efficient treatment of three-body interactions in transcorrelated methods
Evelin Martine Christlmaier, Thomas Schraivogel, Pablo López Ríos +2
An efficient implementation for approximate inclusion of the three-body operator arising in transcorrelated methods via exclusion of explicit three-body components (xTC) is present…
Transcorrelated coupled cluster methods. II. Molecular systems
Thomas Schraivogel, Evelin Martine Christlmaier, Pablo López Ríos +2
We demonstrate the accuracy of ground-state energies of the transcorrelated Hamiltonian, employing sophisticated Jastrow factors obtained from variational Monte Carlo, together wit…
Density Matrix Renormalization Group for Transcorrelated Hamiltonians: Ground and Excited States in \emph{ab initio} Systems
Ke Liao, Huanchen Zhai, Evelin Martine Christlmaier +4
We present the theory of a density matrix renormalization group (DMRG) algorithm which can solve for both the ground and excited states of non-Hermitian transcorrelated Hamiltonian…
Combined unitary and symmetric group approach applied to low-dimensional spin systems
Werner Dobrautz, Vamshi M. Katukuri, Nikolay A. Bogdanov +3
A novel combined unitary and symmetric group approach is used to study the spin- Heisenberg model and related Fermionic systems in a spin-adapted representation, using…
Transcorrelated coupled cluster methods
Thomas Schraivogel, Aron J. Cohen, Ali Alavi +1
Transcorrelated coupled cluster and distinguishable cluster methods are presented. The Hamiltonian is similarity transformed with a Jastrow factor in the first quantisation, which…
Towards efficient and accurate \emph{ab initio} solutions to periodic systems via transcorrelation and coupled cluster theory
Ke Liao, Thomas Schraivogel, Hongjun Luo +2
We propose a streamlined combination scheme of the transcorrelation (TC) and coupled cluster (CC) theory, which not only increases the convergence rate with respect to the basis se…
On the distinguishable cluster approximation for triple excitations
Daniel Kats, Andreas Köhn
The distinguishable cluster approximation applied to coupled cluster doubles equations greatly improves absolute and relative energies. We apply the same approximation to the tripl…