Navigation : 
        
          
    
   Manual 
    
   Input Variables  
    
  - 
   Atomic Orbitals 
    
  - 
   Calculation Modes 
    
  - 
   ClassicalParticles 
    
  - 
   DFTBPlusInterface 
    
  - 
   Execution 
    
  - 
   Hamiltonian 
    
  - 
   Linear Response 
    
  - 
   Math 
    
  - 
   Maxwell 
    
  - 
   MaxwellStates 
    
  - 
   Mesh 
    
  - 
   Output 
    
  - 
   SCF 
    
  - 
   States 
    
  - 
   System 
    
  - 
   Time-Dependent  
    
  -- 
   Absorbing Boundaries 
    
  -- 
   PhotoElectronSpectrum 
    
  -- 
   Propagation  
      --- ArnoldiOrthogonalization 
      --- InteractionTiming 
      --- IonsConstantVelocity 
      --- IonsTimeDependentDisplacements 
      --- MaxwellAbsorbingBoundaries 
      --- MaxwellBoundaryConditions 
      --- MaxwellTDETRSApprox 
      --- MaxwellTDIntervalSteps 
      --- MaxwellTDOperatorMethod 
      --- MaxwellTDSCFThreshold 
      --- MoveIons 
      --- RecalculateGSDuringEvolution 
      --- TDDynamics 
      --- TDEnergyUpdateIter 
      --- TDExponentialMethod 
      --- TDExpOrder 
      --- TDIonicTimeScale 
      --- TDLanczosTol 
      --- TDMaxSteps 
      --- TDMaxwellKSRelaxationSteps 
      --- TDMaxwellTDRelaxationSteps 
      --- TDPhotonicTimeScale 
      --- TDPropagationTime 
      --- TDPropagator 
      --- TDSCFThreshold 
      --- TDStepsWithSelfConsistency 
      --- TDSystemPropagator 
      --- TDTimeStep 
      --- TemperatureFunction 
      --- Thermostat 
      --- ThermostatMass 
  
    
  -- 
   Response 
    
  -- 
   TD Output 
      -- MaxwellFunctions 
      -- TDExternalFields 
      -- TDFreezeDFTUOccupations 
      -- TDFreezeHXC 
      -- TDFreezeOrbitals 
      -- TDFreezeU 
      -- TDFunctions 
      -- TDGlobalForce 
      -- TDScissor 
  
    
  - 
   Utilities 
    
  - 
   Alphabetic Index 
  
    
   Tutorials 
    
   Developers 
    
   Releases 
         
       
    
    
    TDLanczosTol 
    
    
    
    
TDLanczosTol 
Section  Time-Dependent::Propagation  
Type  float 
Default  1e-5 
 
An internal tolerance variable for the Lanczos method. The smaller, the more
precisely the exponential is calculated, and also the bigger the dimension
of the Krylov subspace needed to perform the algorithm. One should carefully
make sure that this value is not too big, or else the evolution will be
wrong.
 
    
         
        
        
        
        Source information
        
         
    
    
electrons/exponential.F90  : 148
 call  parse_variable ( namespace ,  'TDLanczosTol' ,  CNST ( 1 e - 5 ),  te % lanczos_tol ) 
 
     
 
 
 
    
         
        
        
        
        Featured in chapters of the manual: