From 9b1fa6a2fec35c201e3683ff867e71d36d3c5b1a Mon Sep 17 00:00:00 2001 From: Anthony Scemama Date: Tue, 23 Oct 2018 23:43:28 +0200 Subject: [PATCH] User's guide --- docs/source/users_guide.rst | 46 +++++++++++++++---------------------- 1 file changed, 19 insertions(+), 27 deletions(-) diff --git a/docs/source/users_guide.rst b/docs/source/users_guide.rst index abd0df0a..7c2210e4 100644 --- a/docs/source/users_guide.rst +++ b/docs/source/users_guide.rst @@ -5,10 +5,10 @@ The input data is stored in a `EZFIO`_ database. It is a hierarchical data format which uses the hierarchy of the file system to organize the data, stored in a directory. To access the data in the EZFIO file, you can use the provided API (Fortran, -Python, OCaml or bash), or tools such as `qp_edit` provided with the Quantum +Python, OCaml or Bash), or tools such as ``qp_edit`` provided with the Quantum Package. The data in the EZFIO directory is stroed as plain text files, so it can be read with a text editor. -To create an EZFIO directory from scratch, the `qp_create_ezfio_from_xyz` should +To create an EZFIO directory from scratch, the ``qp_create_ezfio_from_xyz`` should be used. qp_create_ezfio_from_xyz @@ -28,8 +28,6 @@ Flags :: [-m int] Spin multiplicity (2S+1) of the molecule. Default is 1. [-o file] Name of the created EZFIO file. [-p string] Name of the pseudopotential - [-build-info] print info about this build and exit - [-version] print the version of this build and exit [-help] print this help text and exit (alias: -?) @@ -54,7 +52,7 @@ qp_set_mo_class Usage :: - qp_set_mo_class EZFIO_DIRECTORY + qp_set_mo_class [FLAGS] EZFIO_DIRECTORY Flags :: @@ -65,8 +63,6 @@ Flags :: [-inact range] Range of inactive orbitals [-q] Query: print the current masks [-virt range] Range of virtual orbitals - [-build-info] print info about this build and exit - [-version] print the version of this build and exit [-help] print this help text and exit (alias: -?) @@ -89,9 +85,9 @@ Virtual To avoid errors, all the MOs should be given a class. The range of MOs are given like the ranges in SLURM commands. For example, -`"[36-53,72-107,126-131]"`. +``"[36-53,72-107,126-131]"``. -To quickly setup a frozen core calculation, the script `qp_set_frozen_core.py` +To quickly setup a frozen core calculation, the script ``qp_set_frozen_core.py`` can be used:: qp_set_frozen_core.py EZFIO_DIRECTORY @@ -108,21 +104,26 @@ Excited states -------------- It is possible to run excited states calculations with the quantum package. To -do this, set the `n_states` variable in the `Determinants` section to the +do this, set the ``n_states`` variable in the ``Determinants`` section to the number of requested states. The selection criterion will be the maximum of the selection criteria for each state. If the Davidson diagonalization has -difficulties to converge, increase the `n_states_diag` variable in the -`Davidson` section. +difficulties to converge, increase the ``n_states_diag`` variable in the +``Davidson`` section. -When computing multiple states, it is good to have the `s2_eig` flag of the -`Determinants` section set to `true`. This will force the Davidson algorithm to +When computing multiple states, it is good to have the ``s2_eig`` flag of the +``Determinants`` section set to ``true``. This will force the Davidson algorithm to choose only vectors with a value of S^2 equal to the ``expected_s2``. Otherwise, different spin states will come out in the diagonalization. +The Quantum Package doesn't take account of the symmetry. Due to numerical +noise, excited states of different symmetries may enter in the calculation. +Note that it is possible to make state-average calculation of states with +different symmetries and/or different spin multiplicities. + To include excited state of all possible symmetries, a simple trick is to run a preliminary multi-state CIS calculation, and then running the selected -FCI restarting from the CIS states, setting the `read_wf` flag of the -`Determinants` section tp `true`. +FCI restarting from the CIS states, setting the ``read_wf`` flag of the +``Determinants`` section to ``true``. Usually, it is good practice to use state-averaged MOs so that all states have MOs of comparable quality. For example, when searching for a singly excited @@ -134,22 +135,13 @@ calculation. Natural orbitals ---------------- -To produce state-average natural orbitals, run +To produce state-average natural orbitals, run :: -``` -qp_run save_natorb file.ezfio -``` + qp_run save_natorb file.ezfio The MOs will be replaced, so the two-electron integrals and the wave function are invalidated as well. - -The QP doesn't take account of the symmetry. For reasons due to numerical noise, -excited states of different symmetries may enter in the calculation. -Note that it is possible to make state-average calculation of states with different -symmetries and/or different spin multiplicities. - - .. _EZFIO: http://gitlab.com/scemama/EZFIO