HF

Hydrogen Fluoride (HF)

Models of HF were made using three levels of ab initio theory. The best ab initio level of theory was the double zeta valence (DZV) because it is the highest basis set for the molecule.


	HF at ab initio level double zeta valence (DZV)

Dipole moments and bond length at each ab initio level of theory.

Theory Level	Dipole (D)	Bond Length ( Å)
6-21G	2.151440	0.99
6-31G	2.301129	0.94
DZV	2.389951	0.92
DZV*	2.021539	0.92

        DZV* - Geometry optimization was done again for HF to generate better dipole moments and bond length.
        Experimental dipole moment for HF: 1.91 D¹
        Experimental bond length for HF: 0.9168 Å²


	HF HOMO Orbital

The HOMO orbital is the highest energy molecular orbital occupied by electrons. In HF, the HOMO orbitals are the double degenerate pi 2px and 2py and pi orbitals.


	HF LUMO Orbital

The LUMO orbital is the lowest energy molecular orbital occupied by electrons. The LUMO is the sigma 2pz orbital.


	Molecular Electrostatic Potential and Partial Atomic Charges

Live display of the molecular electrostatic potential and partial atomic charges using the best optimized geometry (DZV). Red denotes regions of relative negative potential and blue region of relative positive potential.

Vibrational Frequency

The graph below shows the vibrational frequency of HF at 4234.16015 cm^-1 . The experimental vibrational frequency is 4138.32 cm^-1 ³.

Potential of bond stretching for the three ab initio levels of theory

The graphs show the potential energy for all three levels of theory. With increasing theory level the potential energy gets lower. However, from the middle and right graphs, levels 6-31G and DZV look the same. Looking at a closer view, the graph on the right, it shows that DZV, which is the bigger basis set, has a lower potential. The best level of theory is DZV because it has a lower potential.

6-21G	6-31G	DZV

Valence Energy Level Diagram
(click on the link to view the energy level diagram)

References:
(1) Atkins, P.;de Paula, J. Atkin’s Physical Chemistry, 9th ed.W. H. Freeman: New York, 2010
(2) http://cccbdb.nist.gov/ . Experimental data for a given species. HF
(3) http://cccbdb.nist.gov/ . Experimental Vibrational Frequencies data for a given species. HF

Difluoroamine p-Xylene

HOME PAGE

Based on template by A. Herráez as modified by J. Gutow

Page skeleton and JavaScript generated by export to web function using Jmol 12.2.RC3 2011-08-06 04:51 on Feb 29, 2012.

Using directory /Users/student/Desktop/mai/web/HF
  adding JmolPopIn.js
  ...jmolApplet0
      ...adding HF_DZV_SPIN.png
      ...copying
./Jmol.js
         to
/Users/student/Desktop/mai/web/HF/Jmol.js
      ...copying
./JmolApplet.jar
         to
/Users/student/Desktop/mai/web/HF/JmolApplet.jar
      ...copying
file:/Users/student/Desktop/mai/HF_dzv_geo_opt_re.log
         to
/Users/student/Desktop/mai/web/HF/HF_dzv_geo_opt_re.log
      ...adding HF_DZV_SPIN.spt
  ...jmolApplet1
      ...adding HF_HOMO.png
      ...adding HF_HOMO.spt
  ...jmolApplet2
      ...adding HF_LUMO.png
      ...adding HF_LUMO.spt
  ...jmolApplet3
      ...adding HF_electro.png
      ...adding HF_electro.spt