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ab_initio_multiple_spawning_dynamics [2023/01/25 15:21] – nproc_mppx obsolete mayab_initio_multiple_spawning_dynamics [2024/02/14 10:54] (current) – external edit 127.0.0.1
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-====== Ab initio multiple spawning dynamics ======+====== Ab initio multiple spawning dynamics (AIMS) ======
  
 //AIMS// is a multi-state first-principles dynamics program written by\\ //AIMS// is a multi-state first-principles dynamics program written by\\
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 ==== Control.dat ==== ==== Control.dat ====
  
-Control.dat is a fortran NAMELIST file storing the main parameters (in au) of an AIMS simulation. At the end of the file, one can optionally specify user-defined atom types (see below).+Control.dat is a fortran NAMELIST file storing the main parameters (in au) of an AIMS simulation. At the end of the file, one can optionally specify user-defined atom types (see below). Also time steps are in au, 1 au = 0.0241888 femtoseconds.
  
 ^  Initialization  ^^^ ^  Initialization  ^^^
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 |''RestartTime''   |''%%Real (-100.0)%%''      |Time from which to restart in Checkpoint.txt. If disabled, use Last_Bundle.txt.                | |''RestartTime''   |''%%Real (-100.0)%%''      |Time from which to restart in Checkpoint.txt. If disabled, use Last_Bundle.txt.                |
 |''IRndSeed''      |''%%Integer (0)%%''        |Initial condition random number seed.            | |''IRndSeed''      |''%%Integer (0)%%''        |Initial condition random number seed.            |
-|''InitialCond''   |''%%(’NoSample’)%%''       |Read initial conditions from Geometry.dat.       | +|''InitialCond''   |''%%('NoSample')%%''       |Read initial conditions from Geometry.dat.       | 
-|                      |''%%’Wigner’%%''           |Sample from the Wigner distribution of harmonic normal modes in Frequencies.dat.                 | +|                      |''%%'Wigner'%%''           |Sample from the Wigner distribution of harmonic normal modes in Frequencies.dat.                 | 
-|                      |''%%’Quasiclassical’%%''   |As above, for the Quasiclassical distribution.   | +|                      |''%%'Quasiclassical'%%''   |As above, for the Quasiclassical distribution.   | 
-|                      |''%%’Boltzmann’%%''        |As above, for the Boltzmann distribution.        |+|                      |''%%'Boltzmann'%%''        |As above, for the Boltzmann distribution.        |
 |''Temperature''   |''%%Real (0.0)%%''         |Temperature (Kelvin) of the initial conditions.  | |''Temperature''   |''%%Real (0.0)%%''         |Temperature (Kelvin) of the initial conditions.  |
 |Expert parameters:    ||| |Expert parameters:    |||
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 |''EShellOnly''       |''%%Logical (.true.)%%''   |Require spawned trajectories to have same classical energy as parent by adjusting momentum along NACV.                                  | |''EShellOnly''       |''%%Logical (.true.)%%''   |Require spawned trajectories to have same classical energy as parent by adjusting momentum along NACV.                                  |
  
-^  Output  ^^^^+^  Output  ^^^
 ^Parameter                        ^Options (Default)          ^Description                                           ^ ^Parameter                        ^Options (Default)          ^Description                                           ^
 |Common parameters:               ||| |Common parameters:               |||
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 Geometry.dat contains the molecular geometry that will be used in the generation of initial conditions. Optionally, the momenta can also be specified, which is useful if\\ Geometry.dat contains the molecular geometry that will be used in the generation of initial conditions. Optionally, the momenta can also be specified, which is useful if\\
-''%%InitialCond=’NoSample’%%'':+''%%InitialCond='NoSample'%%'':
  
 ''%%UNITS=ANG or UNITS=BOHR %%''\\ ''%%UNITS=ANG or UNITS=BOHR %%''\\
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 ==== FrequenciesMP.dat ==== ==== FrequenciesMP.dat ====
  
-FrequenciesMP.dat contains the normal-mode frequencies and displacements of the molecule in its initial geometry and electronic state (usually the ground state). This information is used in the generation of initial conditions. If ''InitialCond''$\neq$''%%’NoSample’%%'' then either this file, Hessian.dat or Frequencies.dat (Sections [[ab initio multiple spawning dynamics#Hessian.dat|Hessian.dat]] and [[ab initio multiple spawning dynamics#Frequencies.dat|Frequencies.dat]] respectively) must be present. The format of FrequenciesMP.dat follows the Molpro output of a Frequencies calculation:+FrequenciesMP.dat contains the normal-mode frequencies and displacements of the molecule in its initial geometry and electronic state (usually the ground state). This information is used in the generation of initial conditions. If ''InitialCond''$\neq$''%%'NoSample'%%'' then either this file, Hessian.dat or Frequencies.dat (Sections [[ab initio multiple spawning dynamics#Hessian.dat|Hessian.dat]] and [[ab initio multiple spawning dynamics#Frequencies.dat|Frequencies.dat]] respectively) must be present. The format of FrequenciesMP.dat follows the Molpro output of a Frequencies calculation (note: in the first line, the number of normal modes has to be given; the rest is as in the Molpro output):
  
-<code - examples/FrequenciesMP.dat>+<code - FrequenciesMP.dat>
 6 6
                               1 A         2 A         3 A         4 A         5 A                               1 A         2 A         3 A         4 A         5 A
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 1) The first step is to create a molpro input deck that controls how the CASSCF electronic structure calculations are performed. AIMS requires a fairly complicated structure to the molpro deck and it is highly recommended that you use the ethylene CASSCF example as a starting point (section [[ab initio multiple spawning dynamics#examples|examples]]). Control.dat should then be modified for your system and desired simulation parameters (section [[ab initio multiple spawning dynamics#Control.dat|Control.dat]]). 1) The first step is to create a molpro input deck that controls how the CASSCF electronic structure calculations are performed. AIMS requires a fairly complicated structure to the molpro deck and it is highly recommended that you use the ethylene CASSCF example as a starting point (section [[ab initio multiple spawning dynamics#examples|examples]]). Control.dat should then be modified for your system and desired simulation parameters (section [[ab initio multiple spawning dynamics#Control.dat|Control.dat]]).
  
-2) Next, the initial conditions should be defined. This involves providing an initial geometry in Geometry.dat (section [[ab initio multiple spawning dynamics#Geometry.dat|Geometry.dat]]) and normal-mode frequencies and displacements in FrequenciesMP.dat (section [[ab initio multiple spawning dynamics#FrequenciesMP.dat|FrequenciesMP.dat]]), which will be used to generate a phase-space distribution that the initial conditions sample. Alternatively, one can also provide momenta in Geometry.dat and set ''%%InitialCond=’NoSample’%%'' in Control.dat, and directly specify the initial conditions.+2) Next, the initial conditions should be defined. This involves providing an initial geometry in Geometry.dat (section [[ab initio multiple spawning dynamics#Geometry.dat|Geometry.dat]]) and normal-mode frequencies and displacements in FrequenciesMP.dat (section [[ab initio multiple spawning dynamics#FrequenciesMP.dat|FrequenciesMP.dat]]), which will be used to generate a phase-space distribution that the initial conditions sample. Alternatively, one can also provide momenta in Geometry.dat and set ''%%InitialCond='NoSample'%%'' in Control.dat, and directly specify the initial conditions.
  
 3) The AIMS calculation is then initiated by running molpro on the input deck, in the usual fashion. In order to sample different initial conditions, multiple AIMS simulations should be run with different values of the random number seed ''IRndSeed'' (or different Geometry.dat files) - each of these should be run in a unique directory. 3) The AIMS calculation is then initiated by running molpro on the input deck, in the usual fashion. In order to sample different initial conditions, multiple AIMS simulations should be run with different values of the random number seed ''IRndSeed'' (or different Geometry.dat files) - each of these should be run in a unique directory.