Rep:Mod:ZZ1617

NH₃

'Item' Table

         Item               Value     Threshold  Converged?
 Maximum Force            0.000004     0.000450     YES
 RMS     Force            0.000004     0.000300     YES
 Maximum Displacement     0.000072     0.001800     YES
 RMS     Displacement     0.000035     0.001200     YES

Information Table

NH₃

Item	Data
Molecule name	NH3
Calculation method	RB3LYP
Basis set	6-31G(d,p)
Final energy E(RB3LYP)	56.55776873 a.u.
Point Group	C3V

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test molecule

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Anmating vibrations

There are 6 modes expected according to the 3N-6 rule.

Modes with frequency 1693.95nm (#2 and #3 in the picture)are degenerate, Modes with frequency 3589.82nm (#5 and #6 in the picture) are degenerate.

Modes with frequencies 1089.54nm and 1693.95nm (#1, #2, and #3 in the picture) are "bending" vibrations, and modes with frequencies 3461.29nm and 3589.82nm (#4, #5, and #6 in the picture) are "bond stretch" vibrations.

Modes with frequencies 1089.54nm and 3461.29nm (#1 and #4 in the picture) are highly symmetric.

Mode with frequency 1089.54nm (#1 in the picture) is the "umbrella" mode.

4 bands (frequencies: 1089.54nm, 1693.95nm, 3461.29nm, and 3589.82nm) would be expected to see in an experimental spectrum of gaseous ammonia.

Atomic Charges

The charge on the N-atom is -1.125, and the charge on the H-atoms is 0.375.

I would expect a negative charge on the N-atom and positive charge on the H-atom because nitrogen is more electronegative than hydrogen.

N₂

'Item' Table

         Item               Value     Threshold  Converged?
 Maximum Force            0.000001     0.000450     YES
 RMS     Force            0.000001     0.000300     YES
 Maximum Displacement     0.000000     0.001800     YES
 RMS     Displacement     0.000000     0.001200     YES

Information Table

N₂

Item	Data
Molecule name	N2
Calculation method	RB3LYP
Basis set	6-31G(d,p)
Final energy E(RB3LYP)	-109.52359111 a.u.
Point Group	D*H

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Anmating vibrations

N₂

Mode #	Freq(nm)
1	2457.33

H₂

'Item' Table

         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     0.000001     0.001200     YES

Information Table

H₂

Item	Data
Molecule name	H2
Calculation method	RB3LYP
Basis set	6-31G(d,p)
Final energy E(RB3LYP)	-1.17853936 a.u.
Point Group	D*H

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Anmating vibrations

H₂

Mode #	Freq(nm)
1	4465.68

Reaction Energies

Reaction: N₂ + 3H₂ -> 2NH₃ E(NH₃) = 56.55776873 a.u.

2*E(NH₃) = 113.11553746 a.u.

E(N₂) = 109.52359111 a.u.

E(H₂) = 1.17853936 a.u.

3*E(H₂) = 3.53561808 a.u.

ΔE=2*E(NH₃)-[E(N₂)+3*E(H₂)] = 0.05632827 a.u. = 147.89 kJ/mol

Choice of small molecule: F₂

'Item' Table

         Item               Value     Threshold  Converged?
 Maximum Force            0.000128     0.000450     YES
 RMS     Force            0.000128     0.000300     YES
 Maximum Displacement     0.000156     0.001800     YES
 RMS     Displacement     0.000221     0.001200     YES

Information Table

F₂

Item	Data
Molecule name	F2
Calculation method	RB3LYP
Basis set	6-31G(d,p)
Final energy E(RB3LYP)	-199.49825218 a.u.
Point Group	D*H

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Anmating vibrations

F₂

Mode #	Freq(nm)
1	1065.09

Analysis: F₂ molecule only has one mode with frequency 1065.09nm because it is a linear molecule (According to 3N-5 rule, 3*2-5=1 mode). The mode is a "bond stretch" vibration, and it is highly symmetric.

Charge Analysis

The charge for both atoms are 0 (i.e. they are not charged).

F₂ molecule is not charged because it does not have any dipole moment, as expected.

Molecular orbitals

2s² contributes to the MO. It is a MO bonding. It is deep in energy, and the MO is occupied.

2p¹ contributes to the MO. It is a MO anti-bonding. It is deep in energy, and the MO is occupied.

2p⁶ contributes to the MO. It is a MO anti-bonding. It is in the LUMO region, and the MO is unoccupied.

2p⁵ contributes to the MO. It is a MO anti-bonding. It is in the HOMO region, and the MO is occupied.

2p² contributes to the MO. It is a MO anti-bonding. It is deep in energy, and the MO is occupied.