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01381971

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NH3 molecule

information

N-H bond distance=1.01798 Å

H-N-H bond angle=105.741°

calculation method: RB3LYP

basis set: 6-31G(d,p)

final energy E(RB3LYP):-56.44397188 a.u.

RMS Gradient Norm:0.05399560 a.u.

Point Group: C3V

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

Jmol Image

test molecule

Display Vibrations

Questions

1.How many modes do you expect from the 3N-6 rule?

 6

2.Which modes are degenerated (i.e. have the same energy?)

 Modes 2,3 and modes 5,6 are degenerated.

3.Which modes are "bending" vibrations and which are "bond stretch" vibrations?

 Modes 1,2,3 are bending and modes 4,5,6 are stretching.

4.Which mode is highly symmetric?

 Mode 4.

5.One mode is known as the "umbrella" mode, which one is this?

 Mode 1.

6.How many bands would you expect to see in an experimental spectrum of gaseous ammonia?

 4 bands.

Charges on atoms

charge on N:-1.125 charge on H:+0.375

due to N atom is more electronegative than H atom.

charges

H2 Molecule

General Information

H-H bond distance = 0.74279 Å

H-H bond angle = 180°

Calculation Method: RB3LYP

Basis Set: 6-31G(d,p)

Total Energy: -1.15928020 a.u.

RMS Gradient Norm: 0.09719500

Point Group: D*H

Item

        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

Jmol 3D Model

H2 Molecule

Display Vibrations


N2 Molecule

General Information

N-N bond distance = 1.10550 Å

N-N bond angle = 180°

Calculation Method: RB3LYP

Basis Set: 6-31G(d,p)

Total Energy: -109.52359111 a.u.

RMS Gradient Norm: 0.02473091 a.u.

Point Group: D*H

Item

        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

Jmol 3D Model

N2 Molecule

Display Vibrations

Energies for Haber-Bosch process

   E(NH3) = -56.55776870 a.u.
   2*E(NH3)=2*-56.55776870 a.u. = -113.1155370 a.u.
   E(N2) = -109.52359111 a.u.
   E(H2) = -1.17853936 a.u.
   3*E(H2)=3*(-1.17853936 a.u.) = -3.53561808 a.u.
   ΔE = 2*E(NH3)-[E(N2)+3*E(H2)] = -113.1155370+113.05920919 = -0.05632781 a.u. = -147.89  kJ/mol
   
   As ΔE is negative, the product(nh3) is thermodynamically more stable.

BH3 molecule

general information

B-H bond distance=1.19232 Å

H-B-H bond angle=120°

calculation method: RB3LYP

basis set: 6-31G(d,p)

final energy E(RB3LYP):-26.61511243 a.u.

RMS Gradient Norm: 0.00305259 a.u.

Point Group: D3H

Item

        Item               Value     Threshold  Converged?
Maximum Force            0.000004     0.000450     YES
RMS     Force            0.000003     0.000300     YES
Maximum Displacement     0.000017     0.001800     YES
RMS     Displacement     0.000011     0.001200     YES

Jmol image

BH3 Molecule

charges

charge on B atom:+0.297

charges on H atoms:-0.099

display vibration

vibration mode 1

molecular orbital

mo1

mo2

mo3

mo4

mo6