Wave function analysis and single-electron properties

The wave function analyses supported by the BDF are: Mulliken and Lowdin Boolean analysis, including net atomic charge and spin density.

The single-electron properties supported by the BDF are:

SCF：dipole moment, polarizability*, hyperpolarizability*, Musburger spectrum (effective contact density), NMR**
TDDFT：dipole moment of excited states*, vibronic intensity of fluorescence absorption spectra, vibronic intensity of phosphorescence absorption spectra

* Calculated in resp module. ** Calculated in nmr module

More wave function analysis and single electron properties can be done by generating data files in molden format in the scf module with a third party program This is done. Example input.

$scf
rks
dft
 b3lyp
molden
$end

The standard molden format only supports spdfg-type Gaussian basis functions, but has been extended to h-functions in BDF

Effective contact density

The calculation of the effective contact density (ED) requires consideration of both relativistic effects (X2C Hamiltonian in BDF, identified by heff = 21, 22, or 23) and finite size nuclei ( nuclear = 1). An example input at the sf-X2CAU/B3LYP level is as follows

$xuanyuan
 heff
  23
 nuclear
  1
$end

$scf
 rks
 dft
  b3lyp
 grid
  sg1
 reled
  20
$end

where reled calls the calculation of the relativistic property ED. 20 means that the ED is not calculated for light elements with atomic number less than 20, thus saving calculation time. For density generalization calculations, the value of ED is sensitive to the integration grid point and ultra fine or more precise sg1 is recommended.

The ED requires a special treatment of the basis group, see 穆斯堡尔谱 .

molden2aim

Download: https://github.com/zorkzou/Molden2AIM

The purpose of molden2aim is to convert molden files generated by BDF into wfn, wfx, or NBO-47 format data files for various various analyses. It supports spdfghtype Gaussian basis functions as well as ECP.

Multiwfn

Download: http://sobereva.com/multiwfn/

Multiwfn is a powerful wave function analysis program. Molden data files (supporting spdfgh basis functions and pseudopotentials) generated by BDF or wfn, wfx data files transformed by molden2aim, Multiwfn can be used for various wave function analyses, such as electron density topology analysis (also known as quantum theory of atoms in molecules ; QTAIM), electron localization functions (ELF), booster analysis, bond level analysis, atomic charge analysis, etc., and Images of molecular orbitals, electron density and various real space functions can also be plotted. See the Multiwfn user manual for details.

NBO analysis

BDF does not currently contain an interface to NBO (https://nbo7.chem.wisc.edu/), but it is possible to use molden2aim to convert BDF-generated molden files (supporting spdfgh basis functions and pseudopotentials) into NBO-47 format data files, and then use the NBO standalone program gennbo.exe to perform NBO analysis.

For wave functions of the RHF/RKS and UHF/UKS types (i.e., the MO occupation number can only be 0, 1, and 2), NBO can calculate the “Second Order Perturbation Theory Analysis”, which requires the presence of the Fock matrix in the 47 file. To do this, set nbopro=1 in the molden2aim configuration file m2a.ini .