From da7edff3b7875eb08a31d98072f65c668239d492 Mon Sep 17 00:00:00 2001
From: AbdAmmar <abd.ammar.phys@gmail.com>
Date: Tue, 16 Jan 2024 00:02:25 +0100
Subject: [PATCH] added README for Jastrow

---
 plugins/local/jastrow/README.md            | 62 +++++++++++++++++++++-
 plugins/local/non_h_ints_mu/tc_integ.irp.f | 12 ++++-
 2 files changed, 71 insertions(+), 3 deletions(-)

diff --git a/plugins/local/jastrow/README.md b/plugins/local/jastrow/README.md
index aefb6ad5..f3cd363c 100644
--- a/plugins/local/jastrow/README.md
+++ b/plugins/local/jastrow/README.md
@@ -1,3 +1,63 @@
 # Jastrow
 
-Information relative to the Jastrow factor in trans-correlated calculations.
+Information related to the Jastrow factor in trans-correlated calculations.
+
+The main keywords are:
+- `j2e_type`
+- `j1e_type`
+- `env_type`
+
+## j2e_type Options
+
+1. **none:** No 2e-Jastrow is used.
+
+2. **rs-dft:** 2e-Jastrow inspired by Range Separated Density Functional Theory. It has the following shape:
+   \begin{equation}
+   \tau = \frac{1}{2} \sum_{i,j \neq i} u(\mathbf{r}_i, \mathbf{r}_j),
+   \end{equation}
+   with,
+   \begin{equation}
+   u(\mathbf{r}_1, \mathbf{r}_2) = u(r_{12}) = \frac{r_{12}}{2} \left[ 1 - \text{erf}(\mu \, r_{12}) \right] - \frac{\exp\left[- (\mu \, r_{12})^2\right]}{2 \sqrt{\pi} \mu}.
+   \end{equation}
+
+
+
+## env_type Options
+
+The Jastrow used is multiplied by an envelope \(v\):
+
+\begin{equation}
+\tau = \frac{1}{2} \sum_{i,j \neq i} u(\mathbf{r}_i, \mathbf{r}_j) \, v(\mathbf{r}_i) \, v(\mathbf{r}_j)
+\end{equation}
+
+- if `env_type` is **none**: No envelope is used.
+
+- if `env_type` is **prod-gauss**: \(v(\mathbf{r}) = \prod_{a} \left(1 - e^{-\alpha_a (\mathbf{r} - \mathbf{R}_a)^2 } \right)\)
+
+- if `env_type` is **sum-gauss**: \(v(\mathbf{r}) = 1 - \sum_{a} \left(1 - c_a e^{-\alpha_a (\mathbf{r} - \mathbf{R}_a)^2 } \right)\)
+
+Here, \(A\) designates the nuclei, and the coefficients and exponents are defined in the tables `enc_coef` and `env_expo` respectively.
+
+
+
+## j1e_type Options
+
+The Jastrow used is:
+
+\begin{equation}
+\tau = \sum_i u_{1e}(\mathbf{r}_i)
+\end{equation}
+
+- if `j1e_type` is **none**: No one-electron Jastrow is used.
+
+- if `j1e_type` is **gauss**: We use \(u_{1e}(\mathbf{r}) = \sum_A \sum_{p_A} c_{p_A} e^{-\alpha_{p_A} (\mathbf{r} - \mathbf{R}_A)^2}\), where the \(c_p\) and \(\alpha_p\) are defined by the tables `j1e_coef` and `j1e_expo`, respectively.
+
+- if `j1e_type` is **charge-harmonizer**: The one-electron Jastrow factor depends on the two-electron Jastrow factor \(u_{2e}\) such that the one-electron term is added to compensate for the unfavorable effect of altering the charge density caused by the two-electron factor:
+\begin{equation}
+u_{1e}(\mathbf{r}_1) = - \frac{N-1}{2N} \sum_{\sigma} \int d\mathbf{r}_2 \rho^{\sigma}(\mathbf{r}_2) u_{2e}(\mathbf{r}_1, \mathbf{r}_2),
+\end{equation}
+
+Feel free to review and let me know if any further adjustments are needed.
+
+
+
diff --git a/plugins/local/non_h_ints_mu/tc_integ.irp.f b/plugins/local/non_h_ints_mu/tc_integ.irp.f
index 10324251..ee4a7c04 100644
--- a/plugins/local/non_h_ints_mu/tc_integ.irp.f
+++ b/plugins/local/non_h_ints_mu/tc_integ.irp.f
@@ -59,7 +59,11 @@ BEGIN_PROVIDER [double precision, int2_grad1_u12_ao, (ao_num, ao_num, n_points_f
 
       ! ---
 
-      if((j2e_type .eq. "rs-dft") .and. (env_type .eq. "none")) then
+      if(j2e_type .eq. "none") then
+      
+        int2_grad1_u12_ao = 0.d0
+
+      elseif((j2e_type .eq. "rs-dft") .and. (env_type .eq. "none")) then
 
         PROVIDE v_ij_erf_rk_cst_mu x_v_ij_erf_rk_cst_mu
 
@@ -307,7 +311,11 @@ BEGIN_PROVIDER [double precision, int2_grad1_u12_square_ao, (ao_num, ao_num, n_p
 
     ! ---
 
-    if((j2e_type .eq. "rs-dft") .and. (env_type .eq. "none")) then
+    if(j2e_type .eq. "none") then
+
+      int2_grad1_u12_square_ao = 0.d0
+
+    elseif((j2e_type .eq. "rs-dft") .and. (env_type .eq. "none")) then
 
       PROVIDE int2_grad1u2_grad2u2