Intersystem crossing (ISC) Calculation

Overview

MOMAP is able to simulate intersystem crossing (ISC) rate constant, which is based on TVCORF_SPEC [1] and TVSPEC_SPEC subprograms. TVCORF_SPEC subprogram is used to calculate thermal vibration correlation function (TVCF). TVSPEC_SPEC subprogram is used to simulate phosphorescence spectrum.

In the following part, this kind of calculation will be called rad_PL calculation.

Start running calculation

To start a rad_PL calculation, you need a evc.cart.dat file or a evc.dint.dat file, a job control file and a parallel control file. evc.*.dat file is obtained from the previous evc calculation. Job control file is used to generate an input for TVCORF_SPEC and TVSPEC_SPEC subprograms, as well as implement parallel computation. Parallel control file is used to control computation nodes.

There is an example of performing ISC calculation on Ir(ppy)3. The input files can be found in examples/Irppy3. 4 files are required in this example.

  1. evc.cart.dat evc calculation result.
  2. job Generate input file and implement parallel computation. Computation parameters are involved in this file.
  3. run Set file path for job file and nodefile and run the calculation.
  4. examples/config/nodefile Control computation nodes. The file path should be designated in run file. Other examples can be found in examples/6T/spec and examples/porphyrin/spec.

Modifying job file

Here is an example of job file. Control parameters and their functions are listed down below. Change the parameters before performing a rad_PL calculation.

&control
  DUSHIN      = .t.              # Toggle Duschinsky rotation effect
  Temp        = 298 K            # Temperature
  tmax        = 655.36 fs        # Integral interval of correlation function (Must be converged. See section 4.4)
  dt          = 0.01 fs          # Integration step of correlation function (As small as possible)
  Ead         = 0.1008948 au     # Adiabatic energy difference (Able to change unit)
  Hso         = 217.825327 cm-1  # Spin-orbit coupling (SOC) constant
  FreqScale   = 1.0              # Frequency Scaling factor
  logFile     = "log"            # Name of output info file (output)
  DSFile      = "evc.cart.dat"   # Name of evc file (input)
  FtFile      = "ft.dat"         # Name of correlation function info file (output)
  isgauss     = .f.              # Toggle spectrum broadening
  BroadenType = "lorentzian"     # Type of broadening function (lorentz / gauss)
  Broadenfunc = "frequency"      # Type of broadening parameter (freq / time)
  FWHM        = 100 cm-1         # Broadening width (FWHM)
  GFile       = "gsfile"         # Name of broadening info file (output)
  NScale      = 1
  Emin        = -0.3 au          # Lower bound of spectrum
  Emax        = 0.3 au           # Upper bound of spectrum
  dE          = 0.00001 au       # Integration step of spectrum
  FoFile      = "fo.dat"         # Name of spectrum info (output)
/

Verify convergence of correlation function and obtain results

Make sure the correlation function is converged. The verification process can be found in the section Verify convergence of correlation function and obtain results.

Radiative decay rate constant can be found at the end of log file. Intersystem crossing (ISC) rate constant can be found at the beginning of isc.dat file. Phosphorescence spectrum information can be obtained from spec.dat.

[1]TVCORF_SPEC_para subprogram is available for parallel computation.