.. _user-section-tis: The TIS section =============== The ``TIS`` section defines settings for (PP)TIS and (PP)RETIS simulations. .. pyretis-input-example:: TIS .. code-block:: rst TIS settings ------------ aimless = True allowmaxlength = False freq = 0.5 high_accept = True interface_sour = None maxlength = 20000 n_jumps = 8 rgen = rgen rescale_energy = False seed = 1 shooting_moves = ['sh'] sigma_v = -1 zero_momentum = False Keywords for the TIS section ---------------------------- The following keywords can be set for the TIS section: .. |tis_aimless| replace:: :ref:`aimless ` .. |tis_allowmaxlength| replace:: :ref:`allowmaxlength ` .. |tis_freq| replace:: :ref:`freq ` .. |tis_high_accept| replace:: :ref:`high_accept ` .. |tis_interface_sour| replace:: :ref:`interface_sour ` .. |tis_maxlength| replace:: :ref:`maxlength ` .. |tis_n_jumps| replace:: :ref:`n_jumps ` .. |tis_rgen| replace:: :ref:`rgen ` .. |tis_seed| replace:: :ref:`seed ` .. |tis_shooting_moves| replace:: :ref:`shooting_moves ` .. |tis_interface_cap| replace:: :ref:`interface_cap ` .. |tis_sigma_v| replace:: :ref:`sigma_v ` .. |tis_rescale_energy| replace:: :ref:`rescale_energy ` .. |tis_zero_momentum| replace:: :ref:`zero_momentum ` .. _table-tis-keywords: .. table:: Keywords for the TIS section :class: table-striped table-hover +----------------------+---------------------------------------------------+ | Keyword | Description | +======================+===================================================+ | |tis_aimless| | Specify if the shooting is aimless or not. | +----------------------+---------------------------------------------------+ | |tis_allowmaxlength| | Specify if the maximum length should be | | | determined randomly. | +----------------------+---------------------------------------------------+ | |tis_freq| | Define how often time reversal moves are | | | performed. | +----------------------+---------------------------------------------------+ | |tis_interface_sour| | Sets the position of SOUR for Web Throwing. | +----------------------+---------------------------------------------------+ | |tis_high_accept| | Set the Stone Skipping version to use. | +----------------------+---------------------------------------------------+ | |tis_maxlength| | Set the maximum length of the paths generated. | +----------------------+---------------------------------------------------+ | |tis_n_jumps| | Set the number of jumps for SS, WT and WF moves. | +----------------------+---------------------------------------------------+ | |tis_rgen| | Set the random number generator to use. | +----------------------+---------------------------------------------------+ | |tis_seed| | Set a seed for the random number generator. | +----------------------+---------------------------------------------------+ | |tis_rescale_energy| | Selects re-scaling of velocities. | +----------------------+---------------------------------------------------+ | |tis_shooting_moves| | Set the MC shooting moves in each ensemble. | +----------------------+---------------------------------------------------+ | |tis_interface_cap| | Set the cap value for subpaths generated by | | | the WF move. | +----------------------+---------------------------------------------------+ | |tis_sigma_v| | Set standard deviations for the random | | | velocity generation | +----------------------+---------------------------------------------------+ | |tis_zero_momentum| | Specify is momentum should be set to zero when | | | shooting. | +----------------------+---------------------------------------------------+ .. _user-section-tis-aimless: Keyword aimless ^^^^^^^^^^^^^^^ .. pyretis-keyword:: aimless boolean Determines if we are to do aimless shooting or not. If this is set to ``False``, then standard deviations for velocity generation can be set by the :ref:`keyword sigma_v `. Default The default is ``aimless = True``. .. _user-section-tis-allowmaxlength: Keyword allowmaxlength ^^^^^^^^^^^^^^^^^^^^^^ .. pyretis-keyword:: allowmaxlength boolean If ``True``, the maximum length for all paths are set to the value given by the keyword ``maxlength``. If ``False``, the maximum length is determined at random based on the length of the current path we are shooting from. Default The default is ``allowmaxlength = False``. .. _user-section-tis-freq: Keyword freq ^^^^^^^^^^^^ .. pyretis-keyword:: freq float This defines how often time reversal moves are performed: E.g. if ``freq = 0.4`` then 40% of the TIS moves are time reversal. Note that if you are running a RETIS simulation, then the percentage of TIS moves will be modified by the percentage of swapping moves, e.g. the percentage of shooting moves will then be given by :math:`(1 - swapfreq) \times (1 - freq)`. Default No default, this keyword **must** be specified. .. _user-section-tis-interface-sour: Keyword interface_sour ^^^^^^^^^^^^^^^^^^^^^^ .. pyretis-keyword:: interface_sour float This defines the position of the SOUR interface for Web Throwing. It HAS to be smaller then the interface defining the ensemble where WT is used. Note that an improper selection of interface_sour will hinder the sampling efficiency. Default No default, this keyword **must** be specified if WT is used. .. _user-section-tis-high-accept: Keyword high_accept ^^^^^^^^^^^^^^^^^^^ .. pyretis-keyword:: high_accept boolean This select the version of Stone Skipping that is going to be used. Potential High Accept should always been choosen since it is more efficient. Note that the current implementation, due to detailed balance, DOES NOT ALLOW to have multiple shooting methods in the same ensemble. Default The default is ``high_accept = True``. .. _user-section-tis-maxlength: Keyword maxlength ^^^^^^^^^^^^^^^^^ .. pyretis-keyword:: maxlength integer This determines the maximum length of the paths generated. Ideally, no paths should be longer than this value. A value too ristrictive can invalidate detailed balance. Default No default, this keyword **must** be specified. .. _user-section-tis-n-jumps: Keyword n_jumps ^^^^^^^^^^^^^^^ .. pyretis-keyword:: n_jumps integer The number of jumps for Stone Skipping, Wire Fencing and of web for Web Throwing. Default No default, this keyword **must** be specified if Stone Skipping, Wire Fencing or Web Throwing are going to be used. .. _user-section-tis-rgen: Keyword rgen ^^^^^^^^^^^^ .. pyretis-keyword:: rgen string Selection of the random number generator to use. The option allows the use of bias random number generator (mock) or an easy implementation of more advanced random number generators. Default The default is ``rgen = rgen``. .. _user-section-tis-rescale-energy: Keyword rescale_energy ^^^^^^^^^^^^^^^^^^^^^^ .. pyretis-keyword:: rescale_energy float or boolean If this keyword is set to a number, then the velocities are re-scaled so that the total energy is equal to the given number. This is useful for performing NVE simulations. If the keyword is set to ``False``, then the energies will not be re-scaled. Default The default value is ``rescale_energy = False``. .. _user-section-tis-seed: Keyword seed ^^^^^^^^^^^^ .. pyretis-keyword:: seed integer This integer is a seed for the random number generator used in the TIS algorithm (e.g. when selecting a shooting point). Default The default is ``seed = 0``. .. _user-section-tis-shooting-moves: Keyword shooting_moves ^^^^^^^^^^^^^^^^^^^^^^ .. pyretis-keyword:: shooting_moves list of strings This list contains the flags that determines the shooting move to be used for each ensemble. Usable moves are 'sh' for shooting, 'ss' for Stone Skipping, 'wt' for Web Throwing and 'wf' for Wire Fencing. Default The default value is ``[]``. .. _user-section-tis-interface-cap: Keyword interface_cap ^^^^^^^^^^^^^^^^^^^^^^ .. pyretis-keyword:: interface_cap float This defines the position of the cap interface for Wire Fencing. It HAS to be larger than the interface defining the ensemble where WF is used. Note that an inproper selection of interface_cap can hinder the sampling efficiency. Default No default. .. _user-section-tis-sigma-v: Keyword sigma_v ^^^^^^^^^^^^^^^ .. pyretis-keyword:: sigma_v float This keyword can be used to set standard deviations for the random velocity generation if the :ref:`keyword aimless ` is set to ``False``. Default The default value is ``sigma_v = -1``. .. _user-section-tis-zero-momentum: Keyword zero_momentum ^^^^^^^^^^^^^^^^^^^^^ .. pyretis-keyword:: zero_momentum boolean If this keyword is set to ``True``, then the momentum of the system is set to zero after creating random velocities for shooting. If ``False``, this is not done. Default The default is ``zero_momentum = False``.