#+TITLE: Quantum Package Release notes

* Version 2.3

** Changes

  - Introduced DFT-based basis set correction
  - Use OpamPack for OCaml
  - Configure adapted for ARM
  - Added many types of integrals
  - Accelerated four-index transformation
  - Added transcorrelated SCF
  - Added bi-orthonormal transcorrelated CIPSI
  - Added Cholesky decomposition of AO integrals
  - Added CCSD and CCSD(T)
  - Added MO localization
  - Changed coupling parameters for ROHF
  - General Davidson algorithm
  - Accelerated restore_symmetry
  - Point charges in the Hamiltonian
  - Removed cryptokit dependency in OCaml
  - Using now standard convention in RDM
  - Added molecular properties
  - Added GTOs with complex exponent

*** TODO: take from dev
  - Updated version of f77-zmq
  - Started to introduce shells in AOs
  - Added ECMD UEG functional

* Version 2.2

** Changes

  - Python3 replaces Python2
  - Travis CI uses 3 jobs
  - Moved Travis scripts into ~travis~ directory
  - IRPF90 and EZFIO are now git submodules
  - Now basis sets should be downloaded from basis-set-exchange website
  - Added ~bse~ in the installable tools
  - Documentation in ~src/README.rst~
  - Added two-body reduced density matrix
  - Added basis set correction
  - Added CAS-based on-top density functional
  - Improve PT2 computation for excited-states: Mostly 2x2
    diagonalization, and some (n+1)x(n+1) diagonalizations
  - Error bars for stochastic variance and norm of the perturbed wave function
  - Improve PT2-matching for excited-states
  - Compute the overlap of PT2 excited states
  - Renamed SOP into CFG
  - Improved parallelism in PT2 by splitting tasks
  - Use max in multi-state PT2 instead of sum for the selection weight
  - Added seniority
  - Added excitation_max
  - More tasks for distribueted Davidson
  - Random guess vectors in Davidson have zeros to preserve symmetry
  - Disk-based Davidson when too much memory is required
  - Fixed bug in DIIS
  - Fixed bug in molden (Au -> Angs)
  - Fixed bug with non-contiguous MOs in active space and deleter MOs
  - Complete network-free installation
  - Fixed bug in selection when computing full PT2

** User interface

  - Added ~qp_basis~ script to install a basis set from the ~bse~
    command-line tool
  - Introduced ~n_det_qp_edit~, ~psi_det_qp_edit~, and
    ~psi_coef_qp_edit~ to accelerate the opening of qp_edit with
    large wave functions
  - Removed ~etc/ninja.rc~
  - Added flag to specify if the AOs are normalized
  - Added flag to specify if the primitive Gaussians are normalized
  - Added ~lin_dep_cutoff~, the cutoff for linear dependencies
  - Davidson convergence threshold can be adapted from PT2
  - In ~density_for_dft~, ~no_core_density~ is now a logical
  - Default for ~weight_selection~ has changed from 2 to 1
  - Nullify_small_elements in matrices to keep symmetry
  - Default of density functional changed from LDA to PBE
  - Added ~no_vvvv_integrals~ flag
  - Added ~pt2_min_parallel_tasks~ to control parallelism in PT2
  - Added ~print_energy~
  - Added ~print_hamiltonian~
  - Added input for two body RDM
  - Added keyword ~save_wf_after_selection~
  - Added a ~restore_symm~ flag to enforce the restoration of
    symmetry in matrices
  - qp_export_as_tgz exports also plugin codes
  - Added a basis module containing basis set information
  - Added qp_run truncate_wf

** Code

  - Many bug fixes
  - Changed electron-nucleus from ~e_n~ to ~n_e~ in names of variables
  - Changed ~occ_pattern~ to ~configuration~
  - Replaced ~List.map~ by a tail-recursive version ~Qputils.list_map~
  - Added possible imaginary part in OCaml MO coefficients
  - Added ~qp_clean_source_files.sh~ to remove non-ascii characters
  - Added flag ~is_periodic~ for periodic systems
  - Possibilities to handle complex integrals and complex MOs
  - Moved pseuodpotential integrals out of ~ao_one_e_integrals~
  - Removed Schwarz test and added logical functions
    ~ao_two_e_integral_zero~ and ~ao_one_e_integral_zero~
  - Introduced type for ~pt2_data~
  - Banned excitations are used with far apart localized MOs
  - S_z2_Sz is now included in S2
  - S^2 in single precision
  - Added Shank function
  - Added utilities for periodic calculations
  - Added ~V_ne_psi_energy~
  - Added ~h_core_guess~ routine
  - Fixed Laplacians in real space (indices)
  - Added LIB file to add extra libs in plugin
  - Using Intel IPP for sorting when using Intel compiler
  - Removed parallelism in sorting
  - Compute banned_excitations from exchange integrals to accelerate with local MOs