Input text file keywords#

Keywords for the various input sections in the program input file can be listed by means of the print_keyword() class method. Examples are given below.

Tasks#

The different taks below are presented in the same order followed for the Properties description.

Task

Description

scf

Perform a Restricted closed-shell calculation (HF or DFT)

roscf

Perform a Restricted open-shell calculation (HF or DFT)

uscf

Perform a Unrestricted open-shell calculation (HF or DFT)

mp2

Perform a Restricted closed-shell MP2 calculation

romp2

Perform a Restricted open-shell MP2 calculation

ump2

Perform a Unrestricted open-shell MP2 calculation

esp charges

Calculate the ESP charges

resp charges

Calculate the RESP charges

loprop

Calculate the LoProp charges and polarizabilities

optimize

Optimize the geometry in the ground and excited state

response

Calculate response properies with TD-DFT and CPP, such as UV/vis or ECD

exciton

Use the exciton coupling model to calculate absorption and circular dichroism

vibrational

Calculate IR, Raman and resonance Raman spectra

Molecule#

mol = vlx.Molecule()
mol.print_keywords()
                ==========================================================================================                
                  @molecule                                                                                               
                ------------------------------------------------------------------------------------------                
                  charge        integer     net charge                                                                    
                  multiplicity  integer     spin multiplicity                                                             
                  units         string      unit of coordinates, default is Angstrom                                      
                  xyz           multi-line  atom and Cartesian coordinates                                                
                  xyzfile       string      XYZ file name (conflicts with units/xyz)                                      
                ==========================================================================================                

SCF optimization#

Here are printed the keywords for the ScfRestrictedDriver(), the same can be done for the ScfRestrictedOpenDriver() and ScfUnrestrictedDriver()

scf_drv = vlx.ScfRestrictedDriver()
scf_drv.print_keywords()
                ==========================================================================================                
                  @scf                                                                                                    
                ------------------------------------------------------------------------------------------                
                  acc_type                  string      type of SCF convergence accelerator                               
                  max_iter                  integer     maximum number of SCF iterations                                  
                  max_err_vecs              integer     maximum number of DIIS error vectors                              
                  pfon                      boolean     use pFON to accelerate convergence                                
                  pfon_temperature          float       pFON temperature                                                  
                  pfon_delta_temperature    float       pFON delta temperature                                            
                  pfon_nocc                 integer     number of occupied orbitals used in pFON                          
                  pfon_nvir                 integer     number of virtual orbitals used in pFON                           
                  level_shifting            float       level shifting parameter                                          
                  level_shifting_delta      float       level shifting delta                                              
                  conv_thresh               float       SCF convergence threshold                                         
                  eri_thresh                float       ERI screening threshold                                           
                  ovl_thresh                float       AO linear dependency threshold                                    
                  restart                   boolean     restart from checkpoint file                                      
                  filename                  string      base name of output files                                         
                  checkpoint_file           string      name of checkpoint file                                           
                  timing                    boolean     print timing information                                          
                  profiling                 boolean     print profiling information                                       
                  memory_profiling          boolean     print memory usage                                                
                  memory_tracing            boolean     trace memory allocation                                           
                  print_level               integer     verbosity of output (1-3)                                         
                  guess_unpaired_electrons  string      unpaired electrons for initila guess                              
                  point_charges             string      potential file for point charges                                  
                  qm_vdw_params             string      vdw parameter file for QM atoms                                   
                ==========================================================================================                
                  @method settings                                                                                        
                ------------------------------------------------------------------------------------------                
                  ri_coulomb                boolean     use RI-J approximation                                            
                  ri_auxiliary_basis        string      RI-J auxiliary basis set                                          
                  dispersion                boolean     use D4 dispersion correction                                      
                  xcfun                     string      exchange-correlation functional                                   
                  grid_level                integer     accuracy level of DFT grid (1-8)                                  
                  potfile                   string      potential file for polarizable embedding                          
                  solvation_model           string      solvation model                                                   
                  cpcm_grid_per_sphere      sequence    number of C-PCM grid points per sphere                            
                  cpcm_cg_thresh            float       threshold for solving C-PCM charges                               
                  cpcm_epsilon              float       dielectric constant of solvent (C-PCM)                            
                  cpcm_x                    float       parameter for scaling function (C-PCM)                            
                  cpcm_custom_vdw_radii     sequence    custom vdw radii for C-PCM                                        
                  electric_field            sequence    static electric field                                             
                ==========================================================================================                

UV/vis absorption spectrum#

prop = vlx.Absorption()
prop.init_driver()

prop.print_keywords()
                ==========================================================================================                
                  @response                                                                                               
                ------------------------------------------------------------------------------------------                
                  eri_thresh             float       ERI screening threshold                                              
                  batch_size             integer     batch size for Fock build                                            
                  conv_thresh            float       convergence threshold                                                
                  max_iter               integer     maximum number of iterations                                         
                  norm_thresh            float       norm threshold for adding vector                                     
                  lindep_thresh          float       threshold for linear dependence                                      
                  serial_ratio           float       serial ratio as in Amdahl's law                                      
                  use_subcomms           boolean     use subcommunicators for Fock build                                  
                  restart                boolean     restart from checkpoint file                                         
                  filename               string      base name of output files                                            
                  checkpoint_file        string      name of checkpoint file                                              
                  force_checkpoint       boolean     flag for writing checkpoint every iteration                          
                  save_solutions         boolean     save solutions to file                                               
                  timing                 boolean     print timing information                                             
                  profiling              boolean     print profiling information                                          
                  memory_profiling       boolean     print memory usage                                                   
                  memory_tracing         boolean     trace memory allocation                                              
                  print_level            integer     verbosity of output (1-3)                                            
                  non_equilibrium_solv   boolean     toggle use of non-equilibrium solvation for response                 
                  nstates                integer     number of excited states                                             
                  core_excitation        boolean     compute core-excited states                                          
                  num_core_orbitals      integer     number of involved core-orbitals                                     
                  nto                    boolean     analyze natural transition orbitals                                  
                  nto_pairs              integer     number of NTO pairs in NTO analysis                                  
                  nto_cubes              boolean     write NTO cube files                                                 
                  detach_attach          boolean     analyze detachment/attachment density                                
                  detach_attach_cubes    boolean     write detachment/attachment density cube files                       
                  esa                    boolean     compute excited state absorption                                     
                  esa_from_state         integer     the state to excite from (e.g. 1 for S1)                             
                  cube_origin            sequence    origin of cubic grid points                                          
                  cube_stepsize          sequence    step size of cubic grid points                                       
                  cube_points            sequence    number of cubic grid points                                          
                  tamm_dancoff           boolean     use Tamm-Dancoff approximation                                       
                ==========================================================================================                
                  @method settings                                                                                        
                ------------------------------------------------------------------------------------------                
                  ri_coulomb             boolean     use RI-J approximation                                               
                  ri_auxiliary_basis     string      RI-J auxiliary basis set                                             
                  xcfun                  string      exchange-correlation functional                                      
                  grid_level             integer     accuracy level of DFT grid                                           
                  potfile                string      potential file for polarizable embedding                             
                  electric_field         sequence    static electric field                                                
                  solvation_model        string      solvation model                                                      
                  cpcm_grid_per_sphere   sequence    number of C-PCM grid points per sphere                               
                  cpcm_cg_thresh         float       threshold for solving C-PCM charges                                  
                  cpcm_epsilon           float       dielectric constant of solvent (C-PCM)                               
                  cpcm_optical_epsilon   float       optical dielectric constant of solvent (C-PCM)                       
                  cpcm_x                 float       parameter for scaling function (C-PCM)                               
                  cpcm_custom_vdw_radii  sequence    custom vdw radii for C-PCM                                           
                ==========================================================================================                

Complex response solver#

cpp_solver = vlx.ComplexResponse()

cpp_solver.print_keywords()
                ==========================================================================================                
                  @response                                                                                               
                ------------------------------------------------------------------------------------------                
                  eri_thresh             float       ERI screening threshold                                              
                  batch_size             integer     batch size for Fock build                                            
                  conv_thresh            float       convergence threshold                                                
                  max_iter               integer     maximum number of iterations                                         
                  norm_thresh            float       norm threshold for adding vector                                     
                  lindep_thresh          float       threshold for linear dependence                                      
                  serial_ratio           float       serial ratio as in Amdahl's law                                      
                  use_subcomms           boolean     use subcommunicators for Fock build                                  
                  restart                boolean     restart from checkpoint file                                         
                  filename               string      base name of output files                                            
                  checkpoint_file        string      name of checkpoint file                                              
                  force_checkpoint       boolean     flag for writing checkpoint every iteration                          
                  save_solutions         boolean     save solutions to file                                               
                  timing                 boolean     print timing information                                             
                  profiling              boolean     print profiling information                                          
                  memory_profiling       boolean     print memory usage                                                   
                  memory_tracing         boolean     trace memory allocation                                              
                  print_level            integer     verbosity of output (1-3)                                            
                  non_equilibrium_solv   boolean     toggle use of non-equilibrium solvation for response                 
                  a_operator             string      A operator                                                           
                  a_components           string      Cartesian components of A operator                                   
                  b_operator             string      B operator                                                           
                  b_components           string      Cartesian components of B operator                                   
                  frequencies            sequence    frequencies                                                          
                  damping                float       damping parameter                                                    
                ==========================================================================================                
                  @method settings                                                                                        
                ------------------------------------------------------------------------------------------                
                  ri_coulomb             boolean     use RI-J approximation                                               
                  ri_auxiliary_basis     string      RI-J auxiliary basis set                                             
                  xcfun                  string      exchange-correlation functional                                      
                  grid_level             integer     accuracy level of DFT grid                                           
                  potfile                string      potential file for polarizable embedding                             
                  electric_field         sequence    static electric field                                                
                  solvation_model        string      solvation model                                                      
                  cpcm_grid_per_sphere   sequence    number of C-PCM grid points per sphere                               
                  cpcm_cg_thresh         float       threshold for solving C-PCM charges                                  
                  cpcm_epsilon           float       dielectric constant of solvent (C-PCM)                               
                  cpcm_optical_epsilon   float       optical dielectric constant of solvent (C-PCM)                       
                  cpcm_x                 float       parameter for scaling function (C-PCM)                               
                  cpcm_custom_vdw_radii  sequence    custom vdw radii for C-PCM                                           
                ==========================================================================================                

Optimization driver#

opt_drv = vlx.OptimizationDriver(scf_drv)

opt_drv.print_keywords()
                ==========================================================================================                
                  @optimize                                                                                               
                ------------------------------------------------------------------------------------------                
                  coordsys        string      coordinate system                                                           
                  constraints     multi-line  constraints                                                                 
                  check_interval  integer     interval for checking coordinate system                                     
                  trust           float       trust radius to begin with                                                  
                  tmax            float       maximum value of trust radius                                               
                  max_iter        integer     maximum number of optimization steps                                        
                  transition      boolean     transition state search                                                     
                  hessian         string      hessian flag                                                                
                  ref_xyz         string      reference geometry                                                          
                  keep_files      boolean     flag to keep output files                                                   
                  conv_maxiter    boolean     consider converged if max_iter is reached                                   
                  conv_energy     float                                                                                   
                  conv_grms       float                                                                                   
                  conv_gmax       float                                                                                   
                  conv_drms       float                                                                                   
                  conv_dmax       float                                                                                   
                ==========================================================================================