wfn

This keyword controls the details of wave function analysis.

Options

Theoretical Background

In Qbics, quantum chemical calculations will produce a wavefunction and store it in a MWFN file. This is a format that contains all the information about the wavefunction, including the molecular coordinates and orbitals. Qbics can read this file and perform some simple wavefunction analysis:

• Orbital localization: The wavefunction can be localized on atoms. Qbics uses Boys algorithm.
• Orbital component analysis: The wavefunction can be analyzed in terms of the atomic orbitals.

For more kinds of wavefunction analysis, one can use Multiwfn. Qbics are well compitable with Multiwfn.

Input Examples

Example: Wavefunction Analysis for CH₂O

Now we perform a wavefunction analysis for CH₂O. The input file is as follows:

basis
    def2-tzvp
end

wfn
    file wfn-1.mwfn  # The file name.
    print_MO_details # Print more information.
end

mol
    O     -0.00000001     -0.00000000      1.44310862
    C     -0.00000001     -0.00000000      0.24425258
    H      0.00000004      0.93861213     -0.34368060
    H     -0.00000002     -0.93861212     -0.34368059
end

task
    energy b3lyp # Do an energy calculation and generate wavefunction file: wfn-1.mwfn
    wfn          # Do analysis.
end

AFter calculation, there will be 2 MWFN files

• wfn-1.mwfn: Stores the original canonical molecular orbitals;
• wfn-1-loc.mwfn: Stores the localized molecular orbitals.

The output file also contains atomic orbital components:

Molecular orbitals:
   1, occ = 2.000, over 1 centers: O1(99.97%), ==> S(99.91%) + P(0.09%) + D(0.00%) + F(0.00%)
   2, occ = 2.000, over 1 centers: C2(99.87%), ==> S(99.93%) + P(0.07%) + D(0.00%) + F(0.00%)
   3, occ = 2.000, over 1 centers: O1(97.43%), ==> S(81.93%) + P(18.04%) + D(0.02%) + F(0.00%)
   4, occ = 2.000, over 2 centers: C2(59.06%), H3(35.88%), ==> S(68.11%) + P(31.75%) + D(0.13%) + F(0.00%)
   5, occ = 2.000, over 2 centers: C2(59.06%), H4(35.88%), ==> S(68.11%) + P(31.75%) + D(0.13%) + F(0.00%)
   6, occ = 2.000, over 2 centers: O1(58.84%), C2(40.27%), ==> S(29.35%) + P(70.27%) + D(0.34%) + F(0.04%)
   7, occ = 2.000, over 2 centers: O1(67.37%), C2(32.59%), ==> S(0.00%) + P(99.53%) + D(0.45%) + F(0.03%)
   8, occ = 2.000, over 1 centers: O1(85.30%), ==> S(11.42%) + P(88.03%) + D(0.53%) + F(0.02%)