From dc9eb6dcd7cf474cf6e132b4a5f9dacfd12a90ec Mon Sep 17 00:00:00 2001 From: Pierre-Francois Loos Date: Wed, 19 Aug 2020 15:07:33 +0200 Subject: [PATCH] modification in abstract and conclusion --- Manuscript/rsdft-cipsi-qmc.tex | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/Manuscript/rsdft-cipsi-qmc.tex b/Manuscript/rsdft-cipsi-qmc.tex index f1d4f60..b6da8e0 100644 --- a/Manuscript/rsdft-cipsi-qmc.tex +++ b/Manuscript/rsdft-cipsi-qmc.tex @@ -72,10 +72,10 @@ \begin{abstract} By combining density-functional theory (DFT) and wave function theory (WFT) via the range separation (RS) of the interelectronic Coulomb operator, we obtain accurate fixed-node diffusion Monte Carlo (FN-DMC) energies with compact multi-determinant trial wave functions. In particular, we combine here short-range exchange-correlation functionals with a flavor of selected configuration interaction (SCI) known as \emph{configuration interaction using a perturbative selection made iteratively} (CIPSI), a scheme that we label RS-DFT-CIPSI. -One of the take-home messages of the present study is that RS-DFT-CIPSI trial wave functions yield lower fixed-node energies with more compact multi-determinant expansion than CIPSI. +One of the take-home messages of the present study is that RS-DFT-CIPSI trial wave functions yield lower fixed-node energies with more compact multi-determinant expansion than CIPSI, especially for small basis sets. Indeed, as the CIPSI method is relieved from describing the short-range part of the correlation hole around the electron-electron coalescence points, the number of determinants in the trial wave function required to reach a given accuracy is significantly reduced as compared to a conventional CIPSI calculation. -Importantly, by performing various numerical experiments, we evidence that the RS-DFT scheme essentially plays the role of a simple Jastrow factor by mimicking short-range correlation effects. -Considering the 55 atomization energies of the Gaussian-1 benchmark set of molecules, we show that using a fixed value of $\mu=0.5$~bohr$^{-1}$ provides an effective cancellation of errors as well as compact trial wave functions, making the present method a good candidate for the accurate description of large systems. +Importantly, by performing various numerical experiments, we evidence that the RS-DFT scheme essentially plays the role of a simple Jastrow factor by mimicking short-range correlation effects, hence avoiding the burden of performing a stochastic optimization. +Considering the 55 atomization energies of the Gaussian-1 benchmark set of molecules, we show that using a fixed value of $\mu=0.5$~bohr$^{-1}$ provides an effective cancellation of errors as well as compact trial wave functions, making the present method a good candidate for the accurate description of large chemical systems. \end{abstract} \maketitle @@ -967,9 +967,9 @@ the CI coefficients in the presence of a Jastrow factor, but without the burden of performing a stochastic optimization. In addition to the intermediate conclusions drawn in Sec.~\ref{sec:int_ccl}, -we can affirm that varying the range-separation parameter $\mu$ and approaching +we have shown that varying the range-separation parameter $\mu$ and approaching RS-DFT-FCI with CIPSI provides a way to adapt the number of -determinants in the trial wave function, leading always to +determinants in the trial wave function, leading to size-consistent FN-DMC energies. We propose two methods. The first one is for the computation of accurate total energies by a one-parameter optimization of the FN-DMC