1.2k citations · 4k across the 48 of their papers we have counts for
32 papers · 1 filter
Learning the Kohn-Sham map with neural operators for quasi-linear scaling density functional theory
Danish Khan, Maurice D. Hanisch, Nikolai Argatoff +3
Kohn--Sham density functional theory (DFT) underpins electronic-structure simulations, but repeated orbital diagonalizations lead to cubic scaling, restricting quantum calculations…
Size Extensive Auxiliary-Field Quantum Monte Carlo with Perturbative Coupled Cluster Trial Wavefunction
Yichi Zhang, Ankit Mahajan, Yann Damour +1
In this work, we develop a size extensive Auxiliary-Field Quantum Monte Carlo (AFQMC) approach that scales as for local energy evaluation by treating the Coupled Cluster S…
Can phaseless auxiliary-field quantum Monte Carlo with broken symmetry trials describe iron-sulfur clusters?
Eirik F. Kjønstad, Huanchen Zhai, James Shee +2
Phaseless auxiliary-field quantum Monte Carlo (AFQMC) has in several cases been found to perform well on strongly correlated systems. Here, we benchmark the method for three iron-s…
Convergence Analysis of the Stochastic Resolution of Identity: Comparing Hutchinson to Hutch++ for the Second-Order Green's Function
Leopoldo Mejía, Sandeep Sharma, Roi Baer +2
Stochastic orbital techniques offer reduced computational scaling and memory requirements to describe ground and excited states at the cost of introducing controlled statistical er…
Toward linear scaling auxiliary field quantum Monte Carlo with local natural orbitals
Jo S. Kurian, Hong-Zhou Ye, Ankit Mahajan +2
We develop a local correlation variant of auxiliary field quantum Monte Carlo (AFQMC) that is based on local natural orbitals (LNO-AFQMC). In LNO-AFQMC, independent AFQMC calculati…
Response properties in phaseless auxiliary field quantum Monte Carlo
Ankit Mahajan, Jo S. Kurian, Joonho Lee +2
We present a method for calculating first-order response properties in phaseless auxiliary field quantum Monte Carlo (AFQMC) through the application of automatic differentiation (A…
Relativistic semistochastic heat-bath configuration interaction
Xubo Wang, Sandeep Sharma
In this work we present the extension of semistochastic heat-bath configuration interaction (SHCI) to work with any two-component and four-component Hamiltonian. Vertical detachmen…
Selected configuration interaction wave functions in phaseless auxiliary field quantum Monte Carlo
Ankit Mahajan, Joonho Lee, Sandeep Sharma
We present efficient algorithms for using selected configuration interaction (sCI) trial wave functions in phaseless auxiliary field quantum Monte Carlo (ph-AFQMC). These advanceme…
Near-Exact Nuclear Gradients of Complete Active Space Self-Consistent Field Wave Functions
James E. T. Smith, Joonho Lee, Sandeep Sharma
In this paper, we study the nuclear gradients of heat bath configuration interaction self-consistent field (HCISCF) wave functions and use them to optimize molecular geometries for…
Taming the sign problem in auxiliary field quantum Monte Carlo using accurate trial wave functions
Ankit Mahajan, Sandeep Sharma
We explore different ways of incorporating accurate trial wave functions into free projection auxiliary field quantum Monte Carlo (fp-AFQMC). Trial states employed include coupled…
Externally corrected CCSD with renormalized perturbative triples (R-ecCCSD(T)) and density matrix renormalization group and selected configuration interaction external sources
Seunghoon Lee, Huanchen Zhai, Sandeep Sharma +2
We investigate the renormalized perturbative triples correction together with the externally corrected coupled-cluster singles and doubles (ecCCSD) method. We take the density matr…
Efficient local energy evaluation for multi-Slater wave functions in orbital space quantum Monte Carlo
Ankit Mahajan, Sandeep Sharma
Recent developments in selected configuration interaction methods have led to increased interest in using multi-Slater trial wave functions in various quantum Monte Carlo (QMC) met…
The Ground State Electronic Energy of Benzene
Janus J. Eriksen, Tyler A. Anderson, J. Emiliano Deustua +21
We report on the findings of a blind challenge devoted to determining the frozen-core, full configuration interaction (FCI) ground state energy of the benzene molecule in a standar…
Efficient multireference perturbation theory without high-order reduced density matrices
Nick S. Blunt, Ankit Mahajan, Sandeep Sharma
We present a stochastic approach to perform strongly contracted n-electron valence state perturbation theory (SC-NEVPT), which only requires one- and two-body reduced density matri…
Recent developments in the PySCF program package
Qiming Sun, Xing Zhang, Samragni Banerjee +46
PYSCF is a Python-based general-purpose electronic structure platform that both supports first-principles simulations of molecules and solids, as well as accelerates the developmen…
Accurate many-body electronic structure near the basis set limit: application to the chromium dimer
Junhao Li, Yuan Yao, Adam A. Holmes +4
We describe a method for computing near-exact energies for correlated systems with large Hilbert spaces. The method efficiently identifies the most important basis states (Slater d…
Multireference configuration interaction and perturbation theory without reduced density matrices
Ankit Mahajan, Nick S. Blunt, Iliya Sabzevari +1
The computationally expensive evaluation and storage of high-rank reduced density matrices (RDMs) has been the bottleneck in the calculation of dynamic correlation for multireferen…
Fast Semistochastic Heat-Bath Configuration Interaction
Junhao Li, Matt Otten, Adam A Holmes +2
This paper presents in detail our fast semistochastic heat-bath configuration interaction (SHCI) method for solving the many-body Schrodinger equation. We identify and eliminate co…
Faster and lower scaling orbital-space Variational Monte Carlo
Iliya Sabzevari, Sandeep Sharma
In this work, we introduce three algorithmic improvements to reduce the cost and improve the scaling of orbital space variational Monte Carlo (VMC). First, we show that by appropri…
Excited States of Methylene, Polyenes, and Ozone from Heat-Bath Configuration Interaction
Alan D. Chien, Adam A. Holmes, Matthew Otten +3
The electronically excited states of methylene (CH), ethylene (CH), butadiene (CH), hexatriene (CH), and ozone (O) have long proven challenging due…
One-step treatment of spin-orbit coupling and electron correlation in large active spaces
Bastien Mussard, Sandeep Sharma
In this work we demonstrate that the heat bath configuration interaction (HCI) and its semistochastic extension can be used to treat relativistic effects and electron correlation o…
Cheap and near exact CASSCF with large active spaces
James E. T. Smith, Adam A. Holmes, Bastien Mussard +1
We use the recently-developed Heat-bath Configuration Interaction (HCI) algorithm as an efficient active-space solver to perform multi-configuration self-consistent field calculati…
The Python-based Simulations of Chemistry Framework (PySCF)
Qiming Sun, Timothy C. Berkelbach, Nick S. Blunt +9
PySCF is a general-purpose electronic structure platform designed from the ground up to emphasize code simplicity, both to aid new method development, as well as for flexibility in…
Stochastic multi-reference perturbation theory with application to linearized coupled cluster method
Guillaume Jeanmairet, Sandeep Sharma, Ali Alavi
In this article we report a stochastic evaluation of the recently proposed LCC multireference perturbation theory [Sharma S., and Alavi A., J. Chem. Phys. 143, 102815, (2015)]. In…