From 8a5026af683acef49678f7e7de23d112a8c42728 Mon Sep 17 00:00:00 2001
From: eginer <giner.emmanuel@gmail.com>
Date: Sun, 23 Oct 2022 20:51:33 +0200
Subject: [PATCH] added davidson_keywords

---
 src/davidson_keywords/EZFIO.cfg   | 54 +++++++++++++++++++++++++++++++
 src/davidson_keywords/NEED        |  1 +
 src/davidson_keywords/README.rst  |  4 +++
 src/davidson_keywords/input.irp.f | 43 ++++++++++++++++++++++++
 src/davidson_keywords/usef.irp.f  | 33 +++++++++++++++++++
 5 files changed, 135 insertions(+)
 create mode 100644 src/davidson_keywords/EZFIO.cfg
 create mode 100644 src/davidson_keywords/NEED
 create mode 100644 src/davidson_keywords/README.rst
 create mode 100644 src/davidson_keywords/input.irp.f
 create mode 100644 src/davidson_keywords/usef.irp.f

diff --git a/src/davidson_keywords/EZFIO.cfg b/src/davidson_keywords/EZFIO.cfg
new file mode 100644
index 00000000..5df761f3
--- /dev/null
+++ b/src/davidson_keywords/EZFIO.cfg
@@ -0,0 +1,54 @@
+[threshold_davidson]
+type: Threshold
+doc: Thresholds of Davidson's algorithm if threshold_davidson_from_pt2 is false.
+interface: ezfio,provider,ocaml
+default: 1.e-10
+
+[threshold_nonsym_davidson]
+type: Threshold
+doc: Thresholds of non-symetric Davidson's algorithm
+interface: ezfio,provider,ocaml
+default: 1.e-12
+
+[davidson_sze_max]
+type: Strictly_positive_int
+doc: Number of micro-iterations before re-contracting
+default: 15
+interface: ezfio,provider,ocaml
+
+[state_following]
+type: logical
+doc: If |true|, the states are re-ordered to match the input states
+default: False
+interface: ezfio,provider,ocaml
+
+[disk_based_davidson]
+type: logical
+doc: If |true|, a memory-mapped file may be used to store the W and S2 vectors if not enough RAM is availabl
+default: True
+interface: ezfio,provider,ocaml
+
+[n_states_diag]
+type: States_number
+doc: Controls the number of states to consider during the Davdison diagonalization. The number of states is n_states * n_states_diag
+default: 4
+interface: ezfio,ocaml
+
+[n_det_max_full]
+type: Det_number_max
+doc: Maximum number of determinants where |H| is fully diagonalized
+interface: ezfio,provider,ocaml
+default: 1000
+
+[threshold_davidson_from_pt2]
+type: logical
+doc: Thresholds of Davidson's algorithm is set to E(rPT2)*threshold_davidson_from_pt2
+interface: ezfio,provider,ocaml
+default: false
+
+[distributed_davidson]
+type: logical
+doc: If |true|, use the distributed algorithm
+default: True
+interface: ezfio,provider,ocaml
+
diff --git a/src/davidson_keywords/NEED b/src/davidson_keywords/NEED
new file mode 100644
index 00000000..5a3182ed
--- /dev/null
+++ b/src/davidson_keywords/NEED
@@ -0,0 +1 @@
+ezfio_files
diff --git a/src/davidson_keywords/README.rst b/src/davidson_keywords/README.rst
new file mode 100644
index 00000000..cdc7cc1f
--- /dev/null
+++ b/src/davidson_keywords/README.rst
@@ -0,0 +1,4 @@
+=================
+davidson_keywords
+=================
+
diff --git a/src/davidson_keywords/input.irp.f b/src/davidson_keywords/input.irp.f
new file mode 100644
index 00000000..4bd79036
--- /dev/null
+++ b/src/davidson_keywords/input.irp.f
@@ -0,0 +1,43 @@
+
+! ---
+
+BEGIN_PROVIDER [ integer, n_states_diag  ]
+  implicit none
+  BEGIN_DOC
+! Number of states to consider during the Davdison diagonalization
+  END_DOC
+
+  logical                        :: has
+  PROVIDE ezfio_filename
+  if (mpi_master) then
+
+    call ezfio_has_davidson_keywords_n_states_diag(has)
+    if (has) then
+      call ezfio_get_davidson_keywords_n_states_diag(n_states_diag)
+    else
+      print *, 'davidson_keywords/n_states_diag not found in EZFIO file'
+      stop 1
+    endif
+    n_states_diag = max(2,N_states * N_states_diag)
+  endif
+  IRP_IF MPI_DEBUG
+    print *,  irp_here, mpi_rank
+    call MPI_BARRIER(MPI_COMM_WORLD, ierr)
+  IRP_ENDIF
+  IRP_IF MPI
+    include 'mpif.h'
+    integer :: ierr
+    call MPI_BCAST( n_states_diag, 1, MPI_INTEGER, 0, MPI_COMM_WORLD, ierr)
+    if (ierr /= MPI_SUCCESS) then
+      stop 'Unable to read n_states_diag with MPI'
+    endif
+  IRP_ENDIF
+
+  call write_time(6)
+  if (mpi_master) then
+    write(6, *) 'Read  n_states_diag'
+  endif
+
+END_PROVIDER
+
+! ---
diff --git a/src/davidson_keywords/usef.irp.f b/src/davidson_keywords/usef.irp.f
new file mode 100644
index 00000000..fed2ba9b
--- /dev/null
+++ b/src/davidson_keywords/usef.irp.f
@@ -0,0 +1,33 @@
+use bitmasks
+use f77_zmq
+
+
+! ---
+
+BEGIN_PROVIDER [ integer, nthreads_davidson ]
+ implicit none
+ BEGIN_DOC
+ ! Number of threads for Davidson
+ END_DOC
+ nthreads_davidson = nproc
+ character*(32) :: env
+ call getenv('QP_NTHREADS_DAVIDSON',env)
+ if (trim(env) /= '') then
+   read(env,*) nthreads_davidson
+   call write_int(6,nthreads_davidson,'Target number of threads for <Psi|H|Psi>')
+ endif
+END_PROVIDER
+
+! ---
+
+BEGIN_PROVIDER [ double precision, threshold_davidson_pt2 ]
+ implicit none
+ BEGIN_DOC
+ ! Threshold of Davidson's algorithm, using PT2 as a guide
+ END_DOC
+ threshold_davidson_pt2 = threshold_davidson
+
+END_PROVIDER
+
+! ---
+