Added selected MRCI module

src/cipsi_utils/pt2_stoch_routines.irp.f

@@ -212,6 +212,7 @@ subroutine ZMQ_pt2(E, pt2_data, pt2_data_err, relative_error, N_in)
           ipos += 1
         endif
       enddo
+      call write_int(6,pt2_stoch_istate,'State')
       call write_int(6,sum(pt2_F),'Number of tasks')
       call write_int(6,ipos,'Number of fragmented tasks')
 

src/mo_basis/utils.irp.f

@@ -228,7 +228,7 @@ subroutine mo_as_svd_vectors_of_mo_matrix_eig(matrix,lda,m,n,eig,label)
   call dgemm('N','N',ao_num,m,m,1.d0,mo_coef_new,size(mo_coef_new,1),U,size(U,1),0.d0,mo_coef,size(mo_coef,1))
 
   do i=1,m
-    if (eig(i) > 1.d-20) then
+    if (D(i) > 1.d-20) then
       eig(i) = D(i)
     else
       eig(i) = 0.d0

src/mrci/EZFIO.cfg

@@ -0,0 +1,24 @@
+[energy]
+type: double precision
+doc: Calculated Selected CASSD energy
+interface: ezfio
+size: (determinants.n_states)
+
+[energy_pt2]
+type: double precision
+doc: Calculated CASSD energy + PT2
+interface: ezfio
+size: (determinants.n_states)
+
+
+[do_ddci]
+type: logical
+doc: If true, remove purely inactive double excitations
+interface: ezfio,provider,ocaml
+default: False
+
+[do_only_1h1p]
+type: logical
+doc: If true, do only one hole/one particle excitations
+interface: ezfio,provider,ocaml
+default: False

src/mrci/NEED

@@ -0,0 +1,4 @@
+cipsi
+generators_cas
+selectors_full
+davidson_undressed

src/mrci/README.rst

@@ -0,0 +1,17 @@
+====
+mrci
+====
+
+
+|CIPSI| algorithm in the multi-reference CI space (CAS + Singles and Doubles).
+
+
+This module is the same as the :ref:`fci` module, except for the choice of the
+generator and selector determinants.
+
+The inactive, active and virtual |MOs| will need to be set with the
+:ref:`qp_set_mo_class` program.
+
+.. seealso::
+
+    The documentation of the :ref:`fci` module.

src/mrci/class.irp.f

@@ -0,0 +1,8 @@
+BEGIN_PROVIDER [ logical, do_only_cas  ]
+ implicit none
+ BEGIN_DOC
+ ! In the CAS+SD case, always false
+ END_DOC
+ do_only_cas  = .False.
+END_PROVIDER
+

src/mrci/mrci.irp.f

@@ -0,0 +1,64 @@
+program mrci
+  implicit none
+  BEGIN_DOC
+! Selected CAS+Singles and Doubles with stochastic selection
+! and PT2.
+!
+! This program performs a |CIPSI|-like selected |CI| using a
+! stochastic scheme for both the selection of the important Slater
+! determinants and the computation of the |PT2| correction. This
+! |CIPSI|-like algorithm will be performed for the lowest states of
+! the variational space (see :option:`determinants n_states`). The
+! program will stop when reaching at least one the two following
+! conditions:
+!
+! * number of Slater determinants > :option:`determinants n_det_max`
+! * |PT2| < :option:`perturbation pt2_max`
+!
+! The following other options can be of interest:
+!
+! :option:`determinants read_wf`
+!   When set to |false|, the program starts with a ROHF-like Slater
+!   determinant as a guess wave function. When set to |true|, the
+!   program starts with the wave function(s) stored in the |EZFIO|
+!   directory as guess wave function(s).
+!
+! :option:`determinants s2_eig`
+!   When set to |true|, the selection will systematically add all the
+!   necessary Slater determinants in order to have a pure spin wave
+!   function with an |S^2| value corresponding to
+!   :option:`determinants expected_s2`.
+!
+! For excited states calculations, it is recommended to start with
+! :ref:`.cis.` or :ref:`.cisd.` guess wave functions, eventually in
+! a restricted set of |MOs|, and to set :option:`determinants s2_eig`
+! to |true|.
+!
+  END_DOC
+
+  PROVIDE all_mo_integrals
+  if (.not.is_zmq_slave) then
+    PROVIDE psi_det psi_coef
+
+    write(json_unit,json_array_open_fmt) 'fci'
+
+    double precision, allocatable :: Ev(:),PT2(:)
+    allocate(Ev(N_states), PT2(N_states))
+    if (do_pt2) then
+      call run_stochastic_cipsi(Ev,PT2)
+    else
+      call run_cipsi
+    endif
+
+    write(json_unit,json_dict_uopen_fmt)
+    write(json_unit,json_dict_close_fmtx)
+    write(json_unit,json_array_close_fmtx)
+    call json_close
+
+  else
+    PROVIDE pt2_min_parallel_tasks
+
+    call run_slave_cipsi
+
+  endif
+end

src/mrci/save_energy.irp.f

@@ -0,0 +1,10 @@
+subroutine save_energy(E,pt2)
+  implicit none
+  BEGIN_DOC
+! Saves the energy in |EZFIO|.
+  END_DOC
+  double precision, intent(in) :: E(N_states), pt2(N_states)
+  call ezfio_set_mrci_energy(E(1:N_states))
+  call ezfio_set_mrci_energy_pt2(E(1:N_states)+pt2(1:N_states))
+end
+