my changes mostly in SI

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Julien Toulouse 2019-12-17 11:06:48 +01:00
parent 2b071a0406
commit 8902ebfea6
3 changed files with 94 additions and 56 deletions

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@ -536,7 +536,7 @@ with
\end{split} \end{split}
\end{equation} \end{equation}
where $\bpot{}{\Bas}[\n{}{}](\br{})=\bpot{\srLDA}{\Bas}[\n{}{}](\br{})$ or $\bpot{\srPBE}{\Bas}[\n{}{}](\br{})$ and the density is calculated from the HF or KS orbitals. where $\bpot{}{\Bas}[\n{}{}](\br{})=\bpot{\srLDA}{\Bas}[\n{}{}](\br{})$ or $\bpot{\srPBE}{\Bas}[\n{}{}](\br{})$ and the density is calculated from the HF or KS orbitals.
The explicit expressions of these srLDA and srPBE correlation potentials are provided in the {\SI}.} The expressions of these srLDA and srPBE correlation potentials are provided in the {\SI}.}
As evidenced by Eq.~\eqref{eq:QP-corrected}, the present basis-set correction is a non-self-consistent, \textit{post}-{\GW} correction. As evidenced by Eq.~\eqref{eq:QP-corrected}, the present basis-set correction is a non-self-consistent, \textit{post}-{\GW} correction.
Although outside the scope of this study, various other strategies can be potentially designed, for example, within linearized {\GOWO} or self-consistent {\GW} calculations. Although outside the scope of this study, various other strategies can be potentially designed, for example, within linearized {\GOWO} or self-consistent {\GW} calculations.
@ -782,7 +782,7 @@ We hope to report on this in the near future.
%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%
\section*{Supporting Information} \section*{Supporting Information}
%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%
See {\SI} for \titou{the explicit expression of the short-range correlation potentials}, additional graphs reporting the convergence of the ionization potentials of the GW20 subset with respect to the size of the basis set, \titou{and See {\SI} for \titou{the expression of the short-range correlation potentials}, additional graphs reporting the convergence of the ionization potentials of the GW20 subset with respect to the size of the basis set, \titou{and
the numerical data of Tables \ref{tab:GW20_HF} and \ref{tab:GW20_PBE0} (provided in txt and json formats).} the numerical data of Tables \ref{tab:GW20_HF} and \ref{tab:GW20_PBE0} (provided in txt and json formats).}
%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%

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@ -49,11 +49,16 @@
\newcommand{\QP}{\textsc{quantum package}} \newcommand{\QP}{\textsc{quantum package}}
% methods % methods
\newcommand{\HF}{\text{HF}}
\newcommand{\PBEO}{\text{PBE0}}
\newcommand{\evGW}{ev$GW$} \newcommand{\evGW}{ev$GW$}
\newcommand{\qsGW}{qs$GW$} \newcommand{\qsGW}{qs$GW$}
\newcommand{\GOWO}{$G_0W_0$} \newcommand{\GOWO}{$G_0W_0$}
\newcommand{\GW}{$GW$} \newcommand{\GW}{$GW$}
\newcommand{\GnWn}[1]{$G_{#1}W_{#1}$} \newcommand{\GnWn}[1]{$G_{#1}W_{#1}$}
\newcommand{\srLDA}{\text{srLDA}}
\newcommand{\srPBE}{\text{srPBE}}
\newcommand{\Bas}{\mathcal{B}}
% operators % operators
\newcommand{\hH}{\Hat{H}} \newcommand{\hH}{\Hat{H}}
@ -72,6 +77,9 @@
\newcommand{\RH}{R_{\ce{H2}}} \newcommand{\RH}{R_{\ce{H2}}}
\newcommand{\RF}{R_{\ce{F2}}} \newcommand{\RF}{R_{\ce{F2}}}
\newcommand{\RBeO}{R_{\ce{BeO}}} \newcommand{\RBeO}{R_{\ce{BeO}}}
\newcommand{\bE}[2]{\Bar{E}_{#1}^{#2}}
\newcommand{\be}[2]{\Bar{\varepsilon}_{#1}^{#2}}
\newcommand{\bpot}[2]{\Bar{v}_{#1}^{#2}}
% orbital energies % orbital energies
\newcommand{\nDIIS}{N^\text{DIIS}} \newcommand{\nDIIS}{N^\text{DIIS}}
@ -121,7 +129,7 @@
\newcommand{\bSigX}{\boldsymbol{\Sigma}^\text{x}} \newcommand{\bSigX}{\boldsymbol{\Sigma}^\text{x}}
\newcommand{\bSigC}{\boldsymbol{\Sigma}^\text{c}} \newcommand{\bSigC}{\boldsymbol{\Sigma}^\text{c}}
\newcommand{\bSigGW}{\boldsymbol{\Sigma}^\text{\GW}} \newcommand{\bSigGW}{\boldsymbol{\Sigma}^\text{\GW}}
\newcommand{\be}{\boldsymbol{\epsilon}} %\newcommand{\be}{\boldsymbol{\epsilon}}
\newcommand{\bDelta}{\boldsymbol{\Delta}} \newcommand{\bDelta}{\boldsymbol{\Delta}}
\newcommand{\beHF}{\boldsymbol{\epsilon}^\text{HF}} \newcommand{\beHF}{\boldsymbol{\epsilon}^\text{HF}}
\newcommand{\beGW}{\boldsymbol{\epsilon}^\text{\GW}} \newcommand{\beGW}{\boldsymbol{\epsilon}^\text{\GW}}
@ -150,6 +158,8 @@
\renewcommand{\bra}[1]{\ensuremath{\langle #1 \vert}} \renewcommand{\bra}[1]{\ensuremath{\langle #1 \vert}}
\renewcommand{\ket}[1]{\ensuremath{\vert #1 \rangle}} \renewcommand{\ket}[1]{\ensuremath{\vert #1 \rangle}}
\renewcommand{\braket}[2]{\ensuremath{\langle #1 \vert #2 \rangle}} \renewcommand{\braket}[2]{\ensuremath{\langle #1 \vert #2 \rangle}}
\newcommand{\n}[2]{n_{#1}^{#2}}
\newcommand{\rsmu}[2]{\mu_{#1}^{#2}}
\newcommand{\ISCD}{Institut des Sciences du Calcul et des Donn\'ees, Sorbonne Universit\'e, Paris, France} \newcommand{\ISCD}{Institut des Sciences du Calcul et des Donn\'ees, Sorbonne Universit\'e, Paris, France}
@ -189,102 +199,130 @@
\newcommand{\potpbeueg}[0]{\bar{v}_{\text{srPBE}}^{\basis}} \newcommand{\potpbeueg}[0]{\bar{v}_{\text{srPBE}}^{\basis}}
\newcommand{\potpbe}[0]{v^{\text{PBE}}_{\text{c}}} \newcommand{\potpbe}[0]{v^{\text{PBE}}_{\text{c}}}
\section{Complementary short-range correlation potentials}
\section{PBE-based complementary potential $\potpbeueg$} Here, we provide the expressions of the complementary short-range LDA and PBE correlation potentials used in the present work in the case of closed-shell systems.
Here, we provide the explicit expression of the PBE-based complementary potential in the case of closed-shell systems such as the ones studied in the present paper. \subsection{Complementary short-range LDA correlation potential}
The PBE-based correlation energy functional with multideterminant reference (ECMD) has been previously reported in Ref.~\onlinecite{Loos_2019} and is defined by the following equation:
The complementary short-range LDA correlation energy functional with multideterminant reference has the expression~\cite{Toulouse_2005,Paziani_2006}
\begin{equation}
\label{eq:def_lda_tot}
\bE{\srLDA}{\Bas}[\n{}{}] =
\int \n{}{}(\br{}) \be{\text{c,md}}{\srLDA}(\n{}{}(\br{}),\rsmu{}{\Bas}(\br{})) \dbr{},
\end{equation}
with
\begin{equation}
\be{\text{c,md}}{\srLDA}(\n{}{},\rsmu{}{}) = \be{\text{c}}{\srLDA}(\n{}{},\rsmu{}{}) + \Delta^{\text{lr-sr}}(n,\mu),
\end{equation}
with $\be{\text{c,md}}{\srLDA}(\n{}{},\rsmu{}{})$ is the complementary short-range LDA correlation energy functional (with single-determinant reference) and $\Delta^{\text{lr-sr}}(n,\mu)$ is a mixed long-range/short-range contribution, both parametrized in Ref.~\onlinecite{Paziani_2006}.
The corresponding complementary srLDA potential is
\begin{eqnarray}
\bpot{\srLDA}{\Bas}[\n{}{}](\br{}) &=& \frac{\delta \bE{\srLDA}{\Bas}[\n{}{}]}{\delta \n{}{}(\br{})}
\nonumber\\
&=& \be{\text{c,md}}{\srLDA}(\n{}{}(\br{}),\rsmu{}{\Bas}(\br{}))
\nonumber\\
&&+ n(\br{}) \frac{\partial \be{\text{c,md}}{\srLDA}}{\partial n} (\n{}{}(\br{}),\rsmu{}{\Bas}(\br{})).
\end{eqnarray}
The density derivative of $\be{\text{c,md}}{\srLDA}$ is calculated as
\begin{eqnarray}
\frac{\partial \be{\text{c,md}}{\srLDA}}{\partial n} = \frac{\partial \be{\text{c}}{\srLDA}}{\partial n} + \frac{\partial \Delta^{\text{lr-sr}}}{\partial n},
\end{eqnarray}
where $\partial \be{\text{c}}{\srLDA}/\partial n$ is given as a subroutine on Paola Gori-Giorgi's web site (\url{https://www.quantummatter.eu/source-codes-2}) and we have calculated $\partial \Delta^{\text{lr-sr}}/\partial n$ by taking the derivative of Eq. (42) of Ref.~\onlinecite{Paziani_2006}.
\subsection{Complementary short-range PBE correlation potential}
The complementary short-range PBE correlation energy functional with multideterminant reference has the expression~\cite{Loos_2019}
\begin{equation} \begin{equation}
\label{eq:def_pbe} \label{eq:def_pbe}
\efuncbasispbe = \int n({\bf r})\epspbeueg(n({\bf r}),s({\bf r}),\mu^{\basis}(\br{})) d\br{}, \efuncbasispbe = \int n({\bf r})\epspbeueg(n({\bf r}),s({\bf r}),\mu^{\basis}(\br{})) d\br{},
\end{equation} \end{equation}
with, with
\begin{equation} \begin{equation}
\label{eq:def_epsipbeueg} \label{eq:def_epsipbeueg}
\epspbeueg(n,s,\mu) = \frac{\epspbe(n,s)}{1+\beta(n,s)\mu^3}, \epspbeueg(n,s,\mu) = \frac{\epspbe(n,s)}{1+\beta(n,s)\mu^3}.
\end{equation} \end{equation}
where $\epspbe(n,s)$ is the usual PBE correlation functional \cite{Perdew_1996}, $s=\nabla n/n^{4/3}$ is the reduced density gradient, Here, $\epspbe(n,s)$ is the usual PBE correlation functional \cite{Perdew_1996}, $s$ is the reduced density gradient,
\begin{equation} \begin{equation}
\beta(n,s) = \frac{3}{2\sqrt{\pi}(1-\sqrt{2})}\frac{\epspbe(n,s)}{n_2^{\text{UEG}}(n)/n}, \beta(n,s) = \frac{3}{2\sqrt{\pi}(1-\sqrt{2})}\frac{\epspbe(n,s)}{n_2^{\text{UEG}}(n)/n},
\end{equation} \end{equation}
and and
\begin{equation} \begin{equation}
\label{eq:uegotop} \label{eq:uegotop}
n_2^{\text{UEG}}(n)=n^2g_0(r_s) n_2^{\text{UEG}}(n)=n^2g_0(r_\text{s})
\end{equation} \end{equation}
is the on-top pair density of the uniform electron gas (UEG). In Eq.~\eqref{eq:uegotop}, $r_s=(4\pi n/3)^{-1/3}$ the Wigner-Seitz radius and $g_0(r_s)$ is the UEG on-top pair-distribution function. The parametrization of $g_0(r_s)$ is given in Eq.~(46) of Ref.~\onlinecite{Gori-Giorgi_2006}. is the on-top pair density of the uniform electron gas (UEG). In Eq.~\eqref{eq:uegotop}, $g_0(r_\text{s})$ is the UEG on-top pair-distribution function written as a function of the Wigner-Seitz radius $r_\text{s}=(4\pi n/3)^{-1/3}$. We use the parametrization of $g_0(r_\text{s})$ given in Eq.~(46) of Ref.~\onlinecite{Gori-Giorgi_2006}.
The potential of this GGA ECMD complementary functional has the following form: The corresponding complementary srPBE potential is
\begin{equation} \begin{eqnarray}
\begin{split} \potpbeueg[n](\br{})
\potpbeueg[n] &=& \fdv{\efuncbasispbe}{n(\br{})}
& = \fdv{\efuncbasispbe}{n} \nonumber\\
\\ &=& \epspbeueg(n({\bf r}),s({\bf r}),\mu^{\basis}(\br{}))
% & = \frac{\partial n \epspbeueg }{\partial n}- \nabla . \frac{\partial n \epspbeueg }{\partial \nabla n}\\ \nonumber\\
& =\epspbeueg + n \pdv{\epspbeueg }{n}- \nabla \cdot \qty( n \pdv{\epspbeueg}{\nabla n} ). &+& n(\br{}) \pdv{\epspbeueg }{n} (n({\bf r}),s({\bf r}),\mu^{\basis}(\br{}))
\end{split} \nonumber\\
\end{equation} &-& \nabla \cdot \qty( n(\br{}) \pdv{\epspbeueg}{\nabla n} (n({\bf r}),s({\bf r}),\mu^{\basis}(\br{})) ).\,\,\,
Hence, we have to compute two main contributions: the scalar part $\pdv{\epspbeueg}{n}$ and the gradient part $\pdv{\epspbeueg }{\nabla n}$. \end{eqnarray}
Hence, we have to compute the density derivative $\partial \epspbeueg/\partial n$ and the density-gradient derivative $\partial \epspbeueg/\partial \nabla n$.
\subsection{Scalar contribution} \subsubsection{Density derivative}
For the scalar contribution, we simply differenciate Eq.~\eqref{eq:def_epsipbeueg} with respect to the density: From Eq.~\eqref{eq:def_epsipbeueg}, the density derivative is found to be
\begin{equation} \begin{equation}
\pdv{\epspbeueg }{n} \pdv{\epspbeueg }{n}
= \frac{\potpbe}{1+\beta\mu^3} = \frac{1}{1+\beta\mu^3} \pdv{\epspbe}{n}
- \frac{\epspbe \mu^3}{(1+\beta\mu^3)^2} \pdv{\beta}{n}, - \frac{\epspbe \mu^3}{(1+\beta\mu^3)^2} \pdv{\beta}{n},
\end{equation} \end{equation}
where $\potpbe = \pdv{\epspbe}{n}$ and where $\partial \epspbe/\partial n$ is the density derivative of the usual PBE correlation functional, and
\begin{equation} \begin{eqnarray}
\pdv{\beta}{n} \pdv{\beta}{n}
= \frac{3}{2\sqrt{\pi}(1-\sqrt{2})} &=& \frac{3}{2\sqrt{\pi}(1-\sqrt{2})}
\Bigg[ \frac{\potpbe}{n_2^{\text{UEG}}/n} \Bigg[ \frac{1}{n_2^{\text{UEG}}/n} \pdv{\epspbe}{n}
- \frac{\epspbe}{(n_2^{\text{UEG}}/n)^2} \frac{\partial (n_2^{\text{UEG}}/n)}{\partial n} \Bigg]. \nonumber\\
\end{equation} &&\phantom{xxxxx} - \frac{\epspbe}{(n_2^{\text{UEG}}/n)^2} \frac{\partial (n_2^{\text{UEG}}/n)}{\partial n} \Bigg].
The only remaining missing part is the derivative of $n_2^{\text{UEG}}/n$ with respect to the density: \end{eqnarray}
The only remaining missing part is the derivative of $n_2^{\text{UEG}}/n$ which is
\begin{equation} \begin{equation}
\pdv{(n_2^{\text{UEG}}/n)}{n} = \pdv{[n g_0(r_s)]}{n} = g_0(r_s)+ n \pdv{g_0(r_s)}{n}. \pdv{(n_2^{\text{UEG}}/n)}{n} = \pdv{[n g_0(r_\text{s})]}{n} = g_0(r_\text{s})+ n \pdv{g_0(r_\text{s})}{n},
\end{equation} \end{equation}
with with
\begin{equation} \begin{equation}
\pdv{g_0(r_s)}{n} = \pdv{r_s}{n} \pdv{g_0(r_s)}{r_s} = -(6 n^{2}\sqrt{\pi})^{-2/3} \pdv{g_0(r_s)}{r_s}. \pdv{g_0(r_\text{s})}{n} = \pdv{r_\text{s}}{n} \pdv{g_0(r_\text{s})}{r_\text{s}} = -(6 n^{2}\sqrt{\pi})^{-2/3} \pdv{g_0(r_\text{s})}{r_\text{s}}.
\end{equation} \end{equation}
The derivative with respect to $r_s$ can be expressed as Finally, we calculate $\partial g_0(r_\text{s}) /\partial r_\text{s}$ by taking the derivative of Eq.~(46) of Ref.~\onlinecite{Gori-Giorgi_2006}
\begin{equation} \begin{equation}
\begin{aligned} \begin{aligned}
\pdv{g_0(r_s)}{r_s} \pdv{g_0(r_\text{s})}{r_\text{s}}
& = \frac{e^{-F\,r_s}}{2} \big[ (-B + 2 C r_s + 3 D r_s^2 + 4 E r_s^3) & = \frac{e^{-F\,r_\text{s}}}{2} \big[ (-B + 2 C r_\text{s} + 3 D r_\text{s}^2 + 4 E r_\text{s}^3)
\\ \\
& - F (1 - B r_s + C r_s^2 + D r_s^3 + E r_s^4) \big], & - F (1 - B r_\text{s} + C r_\text{s}^2 + D r_\text{s}^3 + E r_\text{s}^4) \big],
\end{aligned} \end{aligned}
\end{equation} \end{equation}
with with $C = 0.0819306$, $F = 0.752411$, $D = -0.0127713$, $E =0.00185898$, and $B = 0.7317 - F$.
\begin{align}
C & = 0.0819306, \\
F & = 0.752411, \\
D & = -0.0127713,\\
E & =0.00185898,\\
B & = 0.7317 - F.
\end{align}
\subsubsection{Density-gradient derivative}
\subsection{Gradient contribution} For the density-gradient derivative, we use the chain rule
For the gradient part, we also used the chain rule:
\begin{equation} \begin{equation}
\pdv{\epspbeueg}{\nabla n} = \pdv{\epspbeueg}{\epspbe}\pdv{\epspbe}{\nabla n}. \pdv{\epspbeueg}{\nabla n} = \pdv{\epspbeueg}{\epspbe}\pdv{\epspbe}{\nabla n},
\end{equation} \end{equation}
The term $\pdv{\epspbe}{\nabla n}$ is already known (\textbf{ref??}), and the partial derivative of $\epspbeueg$ with respect to $\epspbe$ is where $\partial \epspbe/\partial \nabla n$ is the density-gradient derivative of the usual PBE correlation functional, and
\begin{equation} \begin{equation}
\pdv{\epspbeueg}{\epspbe} \pdv{\epspbeueg}{\epspbe}
= \frac{1}{1+\beta\mu^3} = \frac{1}{1+\beta\mu^3}
- \frac{\epspbe \mu^3}{(1+\beta\mu^3)^2} \pdv{\beta}{\epspbe}, - \frac{\epspbe \mu^3}{(1+\beta\mu^3)^2} \pdv{\beta}{\epspbe},
\end{equation} \end{equation}
where with
\begin{equation} \begin{equation}
\pdv{\beta}{\epspbe}= \frac{3}{2\sqrt{\pi}(1-\sqrt{2})}\frac{1}{n_2^{\text{UEG}}/n}. \pdv{\beta}{\epspbe}= \frac{3}{2\sqrt{\pi}(1-\sqrt{2})}\frac{1}{n_2^{\text{UEG}}/n}.
\end{equation} \end{equation}
\section{Additional graphs of the convergence of the IPs of the GW20 subset}
Graphs reporting the convergence of the IPs of each molecule of the GW20 subset at the {\GOWO}@{\HF} and {\GOWO}@{\PBEO} levels are given in Figure~\ref{fig:IP_G0W0HF} and~\ref{fig:IP_G0W0PBE0}, respectively.
\begin{figure*} \begin{figure*}
\includegraphics[width=\linewidth]{IP_G0W0HF} \includegraphics[width=\linewidth]{IP_G0W0HF}
\caption{ \caption{
@ -299,7 +337,7 @@ where
\caption{ \caption{
IPs (in eV) computed at the {\GOWO}@PBE0 (black circles), {\GOWO}@PBE0+srLDA (red squares), and {\GOWO}@PBE0+srPBE (blue diamonds) levels of theory with increasingly large Dunning's basis sets (cc-pVDZ, cc-pVTZ, cc-pVQZ, and cc-pV5Z) for the 20 smallest molecules of the GW100 set. IPs (in eV) computed at the {\GOWO}@PBE0 (black circles), {\GOWO}@PBE0+srLDA (red squares), and {\GOWO}@PBE0+srPBE (blue diamonds) levels of theory with increasingly large Dunning's basis sets (cc-pVDZ, cc-pVTZ, cc-pVQZ, and cc-pV5Z) for the 20 smallest molecules of the GW100 set.
The thick black line represents the CBS value obtained by extrapolation with the three largest basis sets. The thick black line represents the CBS value obtained by extrapolation with the three largest basis sets.
\label{fig:IP_G0W0HF} \label{fig:IP_G0W0PBE0}
} }
\end{figure*} \end{figure*}

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@ -41,9 +41,9 @@ We look forward to hearing from you.
{The main criticism as a reader is that all details of the construction of the total energy correction to the ``finite-size basis difference'' with respect to the CBS limit is absent from the paper (very short Section II-C). The authors refer the reader to previous publications (mainly [57]) dealing with total energies in a CCSD(T) quantum chemistry wavefunction framework with which the Green's function community may not be very familiar with. In particular the construction of a local range-separation parameter related to the diagonal of the ``effective'' 2-electron-operator-in-a-basis ($W^{B}$) would deserve to be somehow explained in the present paper.} {The main criticism as a reader is that all details of the construction of the total energy correction to the ``finite-size basis difference'' with respect to the CBS limit is absent from the paper (very short Section II-C). The authors refer the reader to previous publications (mainly [57]) dealing with total energies in a CCSD(T) quantum chemistry wavefunction framework with which the Green's function community may not be very familiar with. In particular the construction of a local range-separation parameter related to the diagonal of the ``effective'' 2-electron-operator-in-a-basis ($W^{B}$) would deserve to be somehow explained in the present paper.}
\\ \\
\alert{We have included a new subsection (Section II.C.) to include additional details about the present basis set correction. \alert{We have included a new subsection (Section II.C.) to include additional details about the present basis set correction.
In particular, the construction of the range-separation function $\mu(\mathbf{r})$ is detailed as well as the corresponding effective two-electron operator $W(\mathbf{r}_1,\mathbf{r}_2)$.} In particular, the construction of the range-separation function $\mu(\mathbf{r})$ is detailed as well as the corresponding effective two-electron operator $W(\mathbf{r}_1,\mathbf{r}_2)$.
We have also expanded Section II.D. to add more details about the short-range correlation functionals. We have also expanded Section II.D. to add more details about the short-range correlation functionals.
Their corresponding potentials are reported in the Supporting Information. Their corresponding potentials are reported in the Supporting Information.}
\item \item
{Following the previous question, and from a pragmatic point of view, what is needed as an input to construct this basis-set-incompleteness correction, namely this effective local potential of Eq. [31] ? Again the answer is present in equations 4-9 of Ref. [57] but could be summarised in the present paper and possibly simplified in the present case of a perturbation theory based on a input mono-determinental Kohn-Sham or HF description of the many-body wavefunction. This may also give an hint on the cost (scaling) and complexity of the approach. } {Following the previous question, and from a pragmatic point of view, what is needed as an input to construct this basis-set-incompleteness correction, namely this effective local potential of Eq. [31] ? Again the answer is present in equations 4-9 of Ref. [57] but could be summarised in the present paper and possibly simplified in the present case of a perturbation theory based on a input mono-determinental Kohn-Sham or HF description of the many-body wavefunction. This may also give an hint on the cost (scaling) and complexity of the approach. }