Added CASSD

stable/cassd/EZFIO.cfg

@@ -0,0 +1,14 @@
+[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)
+
+
+

stable/cassd/NEED

@@ -0,0 +1,3 @@
+cipsi
+generators_cas
+selectors_cassd

stable/cassd/README.rst

@@ -0,0 +1,19 @@
+=====
+cassd
+=====
+
+
+|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.
+
+

stable/cassd/cassd.irp.f

@@ -0,0 +1,54 @@
+program cassd
+  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
+
+  if (.not.is_zmq_slave) then
+    PROVIDE psi_det psi_coef mo_two_e_integrals_in_map
+
+    if (do_pt2) then
+      call run_stochastic_cipsi
+    else
+      call run_cipsi
+    endif
+
+  else
+    PROVIDE mo_two_e_integrals_in_map
+
+    call run_slave_cipsi
+
+  endif
+end

stable/cassd/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_cassd_energy(E(1:N_states))
+  call ezfio_set_cassd_energy_pt2(E(1:N_states)+pt2(1:N_states))
+end
+