Jerzypilipczuk

NH3

"Display Vibrations"

No charge expected - covalent molecule

NH₃

Information
NH3
More Info
Calculation Method	RB3LYP
Basic Set	6-31G(d,p)
Final Energy	-56.55776873
Point Group	C3v
N-H Bond Length	1.01798
H-N-H Bond Angle	105.74116
Optimisation File	Link

         Item               Value     Threshold  Converged?
 Maximum Force            0.000004     0.000450     YES
 RMS     Force            0.000004     0.000300     YES
 Maximum Displacement     0.000070     0.001800     YES
 RMS     Displacement     0.000033     0.001200     YES
 Predicted change in Energy=-5.785191D-10
 Optimization completed.
    -- Stationary point found.

Questions

-How many modes do you expect from the 3N-6 rule?
3 modes
-Which modes are degenerate (ie have the same energy)?
2 and 3, 5 and 6
-Which modes are "bending" vibrations and which are "bond stretch" vibrations?
Bend: 1, 2 and 3. Stretch: 4, 5 and 6.
-Which mode is highly symmetric?
Mode 5. Symmetric stretch of H atoms around N. 
-One mode is known as the "umbrella" mode, which one is this?
Mode 1. symmetric bend of H atoms about N.
-How many bands would you expect to see in an experimental spectrum of gaseous ammonia?
2 bands. 2 asymmetric modes which produce dipoles.

N₂

N₂ "Display Vibrations"

N₂

Information
N2
More Info
Calculation Method	RB3LYP
Basic Set	6-31G(d,p)
Final Energy	-109.52412868
Point Group	Dinf
Optimisation File	Link

         Item               Value     Threshold  Converged?
 Maximum Force            0.000000     0.000450     YES
 RMS     Force            0.000000     0.000300     YES
 Maximum Displacement     0.000000     0.001800     YES
 RMS     Displacement     0.000000     0.001200     YES
 Predicted change in Energy=-7.296120D-14
 Optimization completed.
    -- Stationary point found.

H₂

H₂ "Display Vibrations"

H₂

Information
H2
More Info
Calculation Method	RB3LYP
Basic Set	6-31G(d,p)
Final Energy	-1.17853934
Point Group	Dinf
Optimisation File	Link

         Item               Value     Threshold  Converged?
 Maximum Force            0.000130     0.000450     YES
 RMS     Force            0.000130     0.000300     YES
 Maximum Displacement     0.000171     0.001800     YES
 RMS     Displacement     0.000241     0.001200     YES
 Predicted change in Energy=-2.130914D-08
 Optimization completed.
    -- Stationary point found.

Energy Calculations

E(NH3)= -56.557768
2*E(NH3)=-113.115537
E(N2)=-109.524128
E(H2)=-1.178539
3*E(H2)=-3.535618
ΔE=2*E(NH3)-[E(N2)+3*E(H2)]=-297131.344823

H₂SiO

H₂SiO "Display Vibrations"

H₂SiO Charges

H₂SiO

Information
H2SiO
More Info
Calculation Method	RB3LYP
Basic Set	6-31G(d,p)
Final Energy	-365.90001403
Point Group	Cs
H-Si Bond Length	1.48652
O-Si Bond Length	1.53172
Optimisation File	Link

         Item               Value     Threshold  Converged?
 Maximum Force            0.000023     0.000450     YES
 RMS     Force            0.000009     0.000300     YES
 Maximum Displacement     0.000025     0.001800     YES
 RMS     Displacement     0.000018     0.001200     YES
 Predicted change in Energy=-5.357805D-10
 Optimization completed.
    -- Stationary point found.

H₂SiO Molecular Orbitals

H2SiO Molecular Orbitals
MO 11	MO 3	MO 7	MO 12	MO 13
Energy: -0.31773. This is the pi system. An overlap of unhybradised p orbitals of Si and O.	Energy: -5.32629. This is a non bonding s orbital of the Si atom.	Energy: -0.92465. This is an sp2 hybrid bonding orbital. It is made up of 3 p and 1 s orbital of the Si atom.	Energy: -0.28497. This is the highest occupied molecular orbitals. There is no orbital overlap and no electron density between atoms of the molecule. The shape of the orbitals suggests a composition of p orbitals. The MO has 2 nodes, positioned antiphase.	Energy: -0.07728. This is the lowest unoccupied molecular orbital. It is an antibonding orbital as there is no electron density between the atoms and no orbital overlap. The orbital has 2 nodes positioned antiphase in relation to eachother.