DOI: 10.25820/data.001111
title: Dataset for “Fully quantum embedding with density functional theory for full configuration interaction quantum Monte Carlo”

description: This data set contains inputs, outputs and integral files used for the initiator full configuration interaction quantum Monte Carlo (i-FCIQMC) and coupled cluster singles and doubles with perturbative triples (CCSD(T)) simulations of lithium hydride (equilibrium and separated), hydrogen fluoride (equilibrium and separated), and the hydrogen fluoride dissociation coordinate. These variously include isolated molecules, full benzene-coordinated molecules, and embedded benzene-coordinated molecules. The quantum monte Carlo simulations were performed using the open-source HANDE-QMC package (http://www.hande.org.uk) and analyzed with HANDE-QMC Python tools contained therein. The projection based embedding calculations were performed with QSoME (https://github.com/Goodpaster/QSoME) with either PySCF (https://sunqm.github.io/pyscf/index.html) or MOLPRO (https://www.molpro.net). All integral files were generated using the cc-pVDZ basis set. Geometries were optimized using Gaussian16 (https://gaussian.com/gaussian16/).
description: Description of methods used for collection/generation of data: 

 - FCIQMC calculations: target population 10 - 10^6 (log steps), timestep range of 9e-7 to 2e-2, real amplitudes were used, initial population = 10, and initiator approximation was used. 

 - Reblocking Analysis: reblock_hande.py was used. Reblocking was started at various iteration numbers, determined by visual inspection of shift vs sum. If optimal reblocking did not occur, the mean value for the projected energy was used from the reblock iteration that had a optimal reblocking on the \sum H_0j N_j. (https://github.com/hande-qmc/hande/tree/master/tools/pyhande) 

 - Isolated systems (Li+, LiH, F-, HF and H-) did not use frozen core approximations in generation of integral files. Embedded systems also did not use frozen core orbitals for the C6H6-Li+, C6H6-LiH, C6H6-HF and C6H6-F- integral files. Canonical (non-embedded) integral files were generated using six frozen core orbitals for C6H6-Li+, C6H6-LiH and seven frozen orbitals for C6H6-HF and C6H6-F-. 

 - Equilibrium geometries were obtained by relaxing the systems. The product and reactants were relaxed independently. The stretched C6H6-H-F geometries were obtained by setting the HF bond length to appropriate values. 

Methods for processing the data: 

 - Raw outputs are provided as HANDE outputs (for FCIQMC data), molpro outputs (integral information), and pyscf outputs (making of fcidumps). HANDE outputs were analyzed using a reblocking analysis script provided by the HANDE-QMC developers (https://github.com/hande-qmc/hande/) (https://github.com/hande-qmc/hande/tree/master/tools/pyhande). All files are plain text. 

Software- or Instrument-specific information needed to interpret the data, including software and hardware version numbers: 
 
 - All files are plain text. 

Standards and calibration information, if appropriate: N/A

Environmental/experimental conditions: N/A

Describe any quality-assurance procedures performed on the data: N/A

People involved with sample collection, processing, analysis and/or submission: 

 - Hayley R. Petras, Daniel S. Graham, Sai Kumar Ramadugu, Jason D. Goodpaster, James J. Shepherd