qp2/RELEASE_NOTES.org

#+TITLE: Quantum Package Release notes

* 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

*** 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

*** 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