saving work in Jastrow part

This commit is contained in:
Pierre-Francois Loos 2020-08-09 15:58:40 +02:00
parent e5fd32c5e3
commit 6d75241ca3
2 changed files with 111 additions and 37 deletions

View File

@ -1,13 +1,98 @@
%% This BibTeX bibliography file was created using BibDesk.
%% http://bibdesk.sourceforge.net/
%% Created for Pierre-Francois Loos at 2020-08-08 08:15:47 +0200
%% Created for Pierre-Francois Loos at 2020-08-09 15:41:06 +0200
%% Saved with string encoding Unicode (UTF-8)
@article{Scemama_2006c,
Author = {Scemama, Anthony and Filippi, Claudia},
Date-Added = {2020-08-09 15:41:04 +0200},
Date-Modified = {2020-08-09 15:41:04 +0200},
Doi = {10.1103/physrevb.73.241101},
Issn = {1550-235X},
Journal = {Phys. Rev. B},
Month = {Jun},
Number = {24},
Publisher = {American Physical Society (APS)},
Title = {Simple and efficient approach to the optimization of correlated wave functions},
Url = {http://dx.doi.org/10.1103/PhysRevB.73.241101},
Volume = {73},
Year = {2006},
Bdsk-Url-1 = {http://dx.doi.org/10.1103/PhysRevB.73.241101},
Bdsk-Url-2 = {http://dx.doi.org/10.1103/physrevb.73.241101}}
@article{Umrigar_2005,
Author = {Umrigar, C. J. and Filippi, Claudia},
Date-Added = {2020-08-09 15:37:17 +0200},
Date-Modified = {2020-08-09 15:37:17 +0200},
Doi = {10.1103/physrevlett.94.150201},
Issn = {1079-7114},
Journal = {Phys. Rev. Lett.},
Month = {Apr},
Number = {15},
Publisher = {American Physical Society (APS)},
Title = {Energy and Variance Optimization of Many-Body Wave Functions},
Url = {http://dx.doi.org/10.1103/PhysRevLett.94.150201},
Volume = {94},
Year = {2005},
Bdsk-Url-1 = {http://dx.doi.org/10.1103/PhysRevLett.94.150201},
Bdsk-Url-2 = {http://dx.doi.org/10.1103/physrevlett.94.150201}}
@article{Toulouse_2007,
Author = {Toulouse, Julien and Umrigar, C. J.},
Date-Added = {2020-08-09 15:36:54 +0200},
Date-Modified = {2020-08-09 15:36:54 +0200},
Doi = {10.1063/1.2437215},
Issn = {1089-7690},
Journal = {J. Chem. Phys.},
Month = {Feb},
Number = {8},
Pages = {084102},
Publisher = {AIP Publishing},
Title = {Optimization of quantum Monte Carlo wave functions by energy minimization},
Url = {http://dx.doi.org/10.1063/1.2437215},
Volume = {126},
Year = {2007},
Bdsk-Url-1 = {http://dx.doi.org/10.1063/1.2437215}}
@article{Toulouse_2008,
Author = {Toulouse, Julien and Umrigar, C. J.},
Date-Added = {2020-08-09 15:36:54 +0200},
Date-Modified = {2020-08-09 15:36:54 +0200},
Doi = {10.1063/1.2908237},
Issn = {1089-7690},
Journal = {J. Chem. Phys.},
Month = {May},
Number = {17},
Pages = {174101},
Publisher = {AIP Publishing},
Title = {Full optimization of Jastrow--Slater wave functions with application to the first-row atoms and homonuclear diatomic molecules},
Url = {http://dx.doi.org/10.1063/1.2908237},
Volume = {128},
Year = {2008},
Bdsk-Url-1 = {http://dx.doi.org/10.1063/1.2908237}}
@article{Umrigar_2007,
Author = {Umrigar, C. J. and Toulouse, Julien and Filippi, Claudia and Sorella, S. and Hennig, R. G.},
Date-Added = {2020-08-09 15:36:54 +0200},
Date-Modified = {2020-08-09 15:36:54 +0200},
Doi = {10.1103/physrevlett.98.110201},
Issn = {1079-7114},
Journal = {Phys. Rev. Lett.},
Month = {Mar},
Number = {11},
Publisher = {American Physical Society (APS)},
Title = {Alleviation of the Fermion-Sign Problem by Optimization of Many-Body Wave Functions},
Url = {http://dx.doi.org/10.1103/PhysRevLett.98.110201},
Volume = {98},
Year = {2007},
Bdsk-Url-1 = {http://dx.doi.org/10.1103/PhysRevLett.98.110201},
Bdsk-Url-2 = {http://dx.doi.org/10.1103/physrevlett.98.110201}}
@article{Pulay_1980,
Author = {Pulay, P{\'e}ter},
Date-Added = {2020-08-08 08:15:42 +0200},
@ -622,20 +707,6 @@
Year = {1977},
Bdsk-Url-1 = {https://doi.org/10.1002/qua.560120826}}
@article{Umrigar_2005,
Author = {Umrigar, C. J. and Filippi, Claudia},
Doi = {10.1103/PhysRevLett.94.150201},
Issn = {1079-7114},
Journal = {Phys. Rev. Lett.},
Month = {Apr},
Number = {15},
Pages = {150201},
Publisher = {American Physical Society},
Title = {{Energy and Variance Optimization of Many-Body Wave Functions}},
Volume = {94},
Year = {2005},
Bdsk-Url-1 = {https://doi.org/10.1103/PhysRevLett.94.150201}}
@article{Huron_1973,
Author = {Huron, B. and Malrieu, J. P. and Rancurel, P.},
Doi = {10.1063/1.1679199},

View File

@ -30,6 +30,8 @@
\newcommand{\fnt}{\footnotetext}
\newcommand{\tabc}[1]{\multicolumn{1}{c}{#1}}
\newcommand{\br}{\mathbf{r}}
\newcommand{\EPT}{E_{\text{PT2}}}
\newcommand{\EDMC}{E_{\text{FN-DMC}}}
\newcommand{\Ndet}{N_{\text{det}}}
@ -514,14 +516,15 @@ The take-home message here is that RS-DFT trial wave functions yield a lower fix
\subsection{Link between RS-DFT and Jastrow factors }
\label{sec:rsdft-j}
%======================================================
The data obtained in Sec.~\ref{sec:fndmc_mu} show that RS-DFT can provide CI coefficients
giving trial wave functions with better nodes than FCI wave functions.
Such behaviour can be compared to the common practice of
re-optimizing the Slater part of a trial wave function in the presence of the Jastrow factor.
In the present paragraph, we would like therefore to elaborate some more on the link between RS-DFT
and wave function optimization with the presence of a Jastrow factor.
The data presented in Sec.~\ref{sec:fndmc_mu} evidence that, in a finite basis, RS-DFT can provide
trial wave functions with better nodes than FCI wave function.
Such behaviour can be directty compared to the common practice of
re-optimizing the multideterminant part of a trial wave function $\Psi$ (the so-called Slater part) in the presence of the exponentiated Jastrow factor $e^`J$. \cite{Umrigar_2005,Scemama_2006c,Umrigar_2007,Toulouse_2007,Toulouse_2008}
Hence, in the present paragraph, we would like to elaborate further on the link between RS-DFT
and wave function optimization in the presence of a Jastrow factor.
\titou{T2: maybe we should mention that we only reoptimize the CI coefficients as it is of common practice to re-optimize more than this.}
Let us assume a fixed Jastrow factor $J({\bf{r}_1}, \hdots , {\bf{r}_N})$,
Let us assume a fixed Jastrow factor $J(\br_1, \ldots , \br_N)$,
and a corresponding Slater-Jastrow wave function $\Phi = e^J \Psi$,
where $\Psi = \sum_I c_I D_I$ is a general linear combination of Slater determinants $D_I$.
The only remaining variational parameters in $\Phi$ are therefore the Slater part $\Psi$.
@ -533,7 +536,7 @@ Such a wave function $\Psi^J$ satisfies the generalized hermitian eigenvalue equ
\begin{equation}
e^{J} H e^{J} \Psi^J = E e^{2J} \Psi^J,
\end{equation}
but also the non-hermitian transcorrelated eigenvalue problem\cite{many_things}
but also the non-hermitian transcorrelated eigenvalue problem \cite{many_things}
\begin{equation}
\label{eq:transcor}
e^{-J} H e^{J} \Psi^J = E \Psi^J,
@ -591,12 +594,12 @@ an impact on the CI coefficients similar to the Jastrow factor.
%%% TABLE II %%%
\begin{table}
\caption{\ce{H2O}, double-zeta basis set. Integrated on-top pair density $\expval{ n_2({\bf r},{\bf r}) }$
\caption{\ce{H2O}, double-zeta basis set. Integrated on-top pair density $\expval{ n_2(\br,\br) }$
for $\Psi^J$ and $\Psi^\mu$ with different values of $\mu$. }
\label{table_on_top}
\begin{ruledtabular}
\begin{tabular}{cc}
$\mu$ & $\expval{ n_2({\bf r},{\bf r}) }$ \\
$\mu$ & $\expval{ n_2(\br,\br) }$ \\
\hline
0.00 & 1.443 \\
0.25 & 1.438 \\
@ -617,7 +620,7 @@ an impact on the CI coefficients similar to the Jastrow factor.
\centering
\includegraphics[width=\columnwidth]{on-top-mu.pdf}
\caption{\ce{H2O}, double-zeta basis set. On-top pair
density $n_2({\bf r},{\bf r})$ along the \ce{O-H} axis,
density $n_2(\br,\br)$ along the \ce{O-H} axis,
for $\Psi^J$ (dashed curve) and $\Psi^\mu$ with different values of $\mu$. }
\label{fig:n2}
\end{figure}
@ -627,7 +630,7 @@ an impact on the CI coefficients similar to the Jastrow factor.
\begin{figure}
\centering
\includegraphics[width=\columnwidth]{density-mu.pdf}
\caption{\ce{H2O}, double-zeta basis set. Density $n({\bf r})$ along
\caption{\ce{H2O}, double-zeta basis set. Density $n(\br)$ along
the \ce{O-H} axis, for $\Psi^J$ (dashed curve) and $\Psi^\mu$ with different values of $\mu$. }
\label{fig:n1}
\end{figure}
@ -639,14 +642,14 @@ report several quantities related to the one- and two-body density of
$\Psi^J$ and $\Psi^\mu$ with different values of $\mu$. First, we
report in Table~\ref{table_on_top} the integrated on-top pair density
\begin{equation}
\expval{ n_2({\bf r},{\bf r}) } = \int \text{d}{\bf r} \,\,n_2({\bf r},{\bf r})
\expval{ n_2(\br,\br) } = \int d\br \,\,n_2(\br,\br)
\end{equation}
where $n_2({\bf r}_1,{\bf r}_2)$ is the two-body density [normalized to $N(N-1)$ where $N$ is the number of electrons]
where $n_2(\br_1,\br_2$ is the two-body density [normalized to $N(N-1)$ where $N$ is the number of electrons]
obtained for both $\Psi^\mu$ and $\Psi^J$.
Then, in order to have a pictorial representation of both the on-top
pair density and the density, we report in Fig.~\ref{fig:n1} and Fig.~\ref{fig:n2}
the plots of the total density $n({\bf r})$ and on-top pair density
$n_2({\bf r},{\bf r})$ along one \ce{O-H} axis of the water molecule.
the plots of the total density $n(\br)$ and on-top pair density
$n_2(\br,\br)$ along one \ce{O-H} axis of the water molecule.
From these data, one can clearly notice several trends.
First, from Table~\ref{table_on_top}, we can observe that the overall
@ -694,7 +697,7 @@ As a conclusion of the first part of this study, we can notice that:
\item the optimal value of $\mu$ depends on the system and the
basis set, and the larger the basis set, the larger the optimal value
of $\mu$,
\item numerical experiments (overlap $\braket{\Psi^\mu}{\Psi^J}$,
\item numerical experiments (overlap $\braket*{\Psi^\mu}{\Psi^J}$,
one-body density, on-top pair density, and FN-DMC energy) indicate
that the RS-DFT scheme essentially plays the role of a simple Jastrow factor,
\ie, mimicking short-range correlation effects. The latter
@ -793,15 +796,15 @@ only depends on the parameters of the determinantal component. Using a
non-size-consistent Jastrow factor, or a non-optimal Jastrow factor will
not introduce an additional error in FN-DMC calculations, although it
will reduce the statistical errors by reducing the variance of the
local energy. Moreover, the integrals involved in the pseudo-potential
local energy. Moreover, the integrals involved in the pseudopotential
are computed analytically and the computational cost of the
pseudo-potential is dramatically reduced (for more detail, see
pseudopotential is dramatically reduced (for more detail, see
Ref.~\onlinecite{Scemama_2015}).
%%% TABLE III %%%
\begin{table}
\caption{FN-DMC energies (in hartree) using the VDZ-BFD basis set
and pseudo-potential of the fluorine atom and the dissociated fluorine
and pseudopotential of the fluorine atom and the dissociated fluorine
dimer, and size-consistency error. }
\label{tab:size-cons}
\begin{ruledtabular}
@ -846,7 +849,7 @@ respect to the spin quantum number $m_s$, but the multiplication by a
Jastrow factor introduces spin contamination if the parameters
for the same-spin electron pairs are different from those
for the opposite-spin pairs.\cite{Tenno_2004}
Again, when pseudo-potentials are used this tiny error is transferred
Again, when pseudopotentials are used this tiny error is transferred
in the FN-DMC energy unless the determinant localization approximation
is used.
@ -882,7 +885,7 @@ impacted by this spurious effect, as opposed to FCI.
In this section, we investigate the impact of the spin contamination
due to the short-range density functional on the FN-DMC energy. We have
computed the energies of the carbon atom in its triplet state
with BFD pseudo-potentials and the corresponding double-zeta basis
with BFD pseudopotentials and the corresponding double-zeta basis
set. The calculation was done with $m_s=1$ (3 $\uparrow$ electrons
and 1 $\downarrow$ electrons) and with $m_s=0$ (2 $\uparrow$ and 2
$\downarrow$ electrons).