Tutorial for Calculating $$h_{ij}^\alpha$$ for Cyclazine

This tutorial provides the calculation procedure for determining $$h_{ij}^\alpha$$ for cyclazine, where i and j represent electronic states, and $$\alpha$$ denotes the normal mode.

Overview

This is a two-part calculation focusing on non-adiabatic coupling (vibration coupling) among electronic states (1 to 5) along normal mode 13. The steps are as follows:

First Input: Calculate the reference values before the geometric distortion, corresponding to $$S_0$$ minimum geometries.
Second Input: Compute $$h_{ij}$$ along $$\alpha = 13$$.

Numerical Differentiation

Numerical differentiation is employed using the formula: $$\frac{f(Q_0 + \Delta Q) - f(Q_0)}{\Delta Q}$$ where $$\Delta Q = 0.0001$$.

Important Considerations

Dimension of $$\Delta Q$$: Assume $$\Delta Q$$ is in Angstroms.
Conversion to Bohr: $$\Delta t$$ should be in Bohr, approximately 0.0001889726, as indicated in the mode13-0.00001.inp file.

Calculation Steps

First Input: Calculates the reference values before the geometric distortion, corresponding to $$S_0$$ minimum geometries.
Second Input: Computes $$h_{ij}$$ along $$\alpha = 13$$.

Follow the order of the inputs as listed on this page to ensure accurate results.

[input]
basis=6-31g*
functional=bhhlyp
method=tdhf
runtype=energy
system=ref.xyz

[guess]
save_mol=True
continue_geom=False

[scf]
type=rohf
multiplicity=3
save_molden=True

[dftgrid]
rad_npts=96
ang_npts=302

[tdhf]
type=mrsf
multiplicity=1
nstate=5
tlf=2

[properties]
export=True

[input] Section

system: This is the coordination of your system, your system's coordination can be achieved through two primary methods for OpenQP. The first method employs the Standard Cartesian format, as illustrated in the provided example. The second method utilizes the .XYZ format. To leverage the.XYZ format, save your coordination details in this format within your input folder, for instance, H2O.xyz. Subsequently, it can be easily applied by specifying system=ref.xyz in your input file. Here is an example of.XYZ format:

22
cyclazine at min geom.
C        0.000000000     -1.215095942      0.701535968
C        0.000000000     -2.420355362     -1.397392821
C        0.000000000      0.000000000     -1.403071935
C        0.000000000      2.420355362     -1.397392821
C        0.000000000      1.215095942      0.701535968
C        0.000000000      0.000000000      2.794785642
C        0.000000000     -2.420109052     -0.018527226
C        0.000000000      1.226099574     -2.086612305
C        0.000000000      1.194009477      2.105139530
C        0.000000000     -1.194009477      2.105139530
C        0.000000000     -1.226099574     -2.086612305
C        0.000000000      2.420109052     -0.018527226
N        0.000000000      0.000000000      0.000000000
H        0.000000000      3.354080951     -1.936479538
H        0.000000000      0.000000000      3.872959082
H        0.000000000     -3.354080951     -1.936479538
H        0.000000000     -3.333448128      0.550067590
H        0.000000000      1.190351556     -3.161884557
H        0.000000000      2.143096573      2.611816967
H        0.000000000     -2.143096573      2.611816967
H        0.000000000     -1.190351556     -3.161884557
H        0.000000000      3.333448128      0.550067590

charge: The total charge of the system. A value of 0 indicates that the molecule is neutral, with no net charge.
runtype: Specifies the type of calculation. energy means that the computation aims to determine the electronic energy of the molecule without performing geometry optimization or calculating properties like gradients or Hessians.
basis: The basis set used for the calculation, 6-31gs in this case. The 6-31gs is a split-valence basis set with polarization functions on heavy atoms, designed to provide a good balance between accuracy and computational cost. You can find all of the basis-sets supported by OpenQP within the basis_set folder. Note that the basis-set file names are like 6-31g* -> 6-31g*, 6-31g** -> 6-31g(d,p) so there are no * at all.

[guess] Section

save_mo: 'True', saves complete calculation data to json file.
continue_geom: 'False', uses the input structure (default)

[scf] Section

multiplicity: A multiplicity of 1 indicates a singlet state and 3 is a triplet state.
type: The ROHF (Restricted Open-Shell Hartree-Fock) method is selected for the SCF calculations. ROHF is appropriate for systems with unpaired electrons, providing a wave function that is an eigenfunction of the total spin operator while maintaining restricted orbital occupancies for paired electrons.

[tdhf] Section

nstate: The number of states for which the energy will be calculated, including the ground state. A value of 3 means the calculation will cover the ground state and two excited states, providing insight into the low-lying electronic excitations of the molecule.
multiplicity: sets the multiplicity of the response state.
type: Uses the type of the time-dependent wavefunction. which in this case is mixed-reference spin-flip

[properties] Section

export: saves the computed data to text files

Second Input

[input]
basis=6-31g*
functional=bhhlyp
method=tdhf
runtype=nacme
system=mode13-0.0001.xyz

[guess]
type=json
file=ref.json
file2=ref.json
save_mol=True
continue_geom=False

[scf]
type=rohf
multiplicity=3
save_molden=True

[dftgrid]
rad_npts=96
ang_npts=302

[tdhf]
type=mrsf
multiplicity=1
nstate=5
tlf=2

[properties]
export=True

[nac]
states=1 3
dt=0.0001889726

[input] Section

runtype: computes NAC along the distortion dt (in this case Bohr dimension), while runtype=NAC computes the entire NAC vector along all Cartesian distortion.
system

22
Displacement 0.0001 Å:
CARBON             0.000000000        -1.215100792         0.701527504
CARBON             0.000000000        -2.420355294        -1.397393044
CARBON             0.000000000         0.000009734        -1.403071935
CARBON             0.000000000         2.420355431        -1.397392597
CARBON             0.000000000         1.215091092         0.701544431
CARBON             0.000000000        -0.000000220         2.794785642
CARBON             0.000000000        -2.420117285        -0.018523993
CARBON             0.000000000         1.226100850        -2.086621100
CARBON             0.000000000         1.194016438         2.105145070
CARBON             0.000000000        -1.194002516         2.105133990
CARBON             0.000000000        -1.226098298        -2.086603508
CARBON             0.000000000         2.420100819        -0.018530458
NITROGEN           0.000000000         0.000000017         0.000000000
HYDROGEN           0.000000000         3.354086994        -1.936468954
HYDROGEN           0.000000000        -0.000012049         3.872959082
HYDROGEN           0.000000000        -3.354074906        -1.936490123
HYDROGEN           0.000000000        -3.333455214         0.550072580
HYDROGEN           0.000000000         1.190350779        -3.161893247
HYDROGEN           0.000000000         2.143104535         2.611820538
HYDROGEN           0.000000000        -2.143088611         2.611813395
HYDROGEN           0.000000000        -1.190352330        -3.161875866
HYDROGEN           0.000000000         3.333441043         0.550062600

[guess] Section

file: 'True', name or absolute path to molden or json file.
continue_geom: 'False', uses the input structure (default).
save_mo: 'True', saves complete calculation data to json file.

[nac] Section

states: Specifies the combination of states for each NAC calculation.
dt: distorsion.

Back

MRSF TDDFT NACME - Open-Quantum-Platform/openqp GitHub Wiki

Tutorial for Calculating $$h_{ij}^\alpha$$ for Cyclazine

Overview

Numerical Differentiation

Important Considerations

Calculation Steps

⚠️ GitHub.com Fallback ⚠️

MRSF TDDFT NACME - Open-Quantum-Platform/openqp GitHub Wiki

Tutorial for Calculating $$h_{ij}^\alpha$$ for Cyclazine

Overview

Numerical Differentiation

Important Considerations

Calculation Steps

⚠️ **GitHub.com Fallback** ⚠️

⚠️ GitHub.com Fallback ⚠️