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BH3

RB3LYP/6-31G(d,p) level

Summary Table


         Item               Value     Threshold  Converged?
 Maximum Force            0.000014     0.000450     YES
 RMS     Force            0.000007     0.000300     YES
 Maximum Displacement     0.000055     0.001800     YES
 RMS     Displacement     0.000027     0.001200     YES

Item Table


Frequency Table

Low frequencies ---   -7.9073   -1.6385   -0.0055    0.6256    6.5697    6.7709
Low frequencies --- 1162.9662 1213.1623 1213.1650

Frequency analysis log file YUHANJIN_BH3_OPT_631DP_-_COPY_EDITED_D3H_FREQ.LOG


Borane


The following four images show the calculated MOs for BH3.


Ng611 (talk) 00:56, 15 May 2019 (BST) Which calculated MOs correlate to which MOs on the orbital diagram?

The picture above was taken from Tutorial problems for Lecture 4, made by Prof. Patricia Hunt.

The size of atoms in real MOs is more realistic as three H atoms are much smaller than B as shown. In LCAO, size of atoms will change in order to indicate the contribution of particular atom to the MOs;

Also, the diffusion of electron density could be proven by real MOs since we could see a total red 'sphere' for 2a1' orbital.

The rest two orbitals are quite similar for both LCAO and real MOs.



NH3 and NH3BH3


Ng611 (talk) 00:58, 15 May 2019 (BST) We also needed frequency log files, convergence tables, low frequencies, and jmol images for both of these molecules.

E(NH3)= -56.55777 a.u. E(BH3)= -26.61532 a.u. E(NH3BH3)= -81.99676 a.u.

Ng611 (talk) 00:58, 15 May 2019 (BST) BH3 and NH3 values are good, but the energy of your BH3NH3 adduct is off by quite a bit.

Association Energy ΔE=E(NH3BH3)-[E(NH3)+E(BH3)] = 1.17633 a.u. = 738kJ/mol Based on the calculation, the bond strength of B-N bond is strong. With comparison of N-N 167 kJ/mol and B-B 293 kJ/mol. (accessed at http://www.wiredchemist.com/chemistry/data/bond_energies_lengths.html) Therefore, the B-N bond has ionic character which strengthen the bond.

Ng611 (talk) 01:00, 15 May 2019 (BST) I'd choose different comparisons. An isoelectronic bond would have been more appropriate. Also, you should use book sources where possible.

NI3

RB3LYP/Gen level

Summary Table


         Item               Value     Threshold  Converged?
 Maximum Force            0.000102     0.000450     YES
 RMS     Force            0.000075     0.000300     YES
 Maximum Displacement     0.000667     0.001800     YES
 RMS     Displacement     0.000490     0.001200     YES

Item Table


Low frequencies ---  -12.3847  -12.3783   -5.6131   -0.0040    0.0194    0.0711
Low frequencies ---  100.9307  100.9314  147.2333

Frequency analysis log file YUHANJIN_NI3_OPT_GEN_FREQ3.LOG


NI3

The optimised N-I bond distance is 2.184 Å

Metal Carbonyls

Ng611 (talk) 01:13, 15 May 2019 (BST) Several parts of this section are missing. You needed to include overall charges in your calculations (where apprpriate, e.g.: your Ti and Fe complexes). You also needed to perform an LCAO decomposition on your complex MOs, and choose (and explain) a relevant trend.

RB3LYP/Gen

[Ti(CO)6]2-

Summary table


Bond length (Ti-C) = 2.160 Å

Vibrational frequencies:

Low frequencies ---   -3.6954   -0.0013   -0.0011   -0.0009   12.8157   12.8159
Low frequencies ---   15.4924   15.4925   29.1347

Frequency analysis log file TICO_GEN_OPT_FREQ.LOG

Ng611 (talk) 01:02, 15 May 2019 (BST) You're missing your conversion table here.

Three diagrams below showing three valence MOs calculated.


This MO is HOMO of [Ti(CO)6]2-. The overall bonding is strong anti-bonding character. There is in-ligand pi-antibonding on four ligands in the plane and ligand-ligand pi-antibonding.


Overall MO bonding is anti-bonding character. There is in-ligand pi-antibonding on four ligands in the plane. There is a 'donut-like' MO along the z-axis. The ligand-ligand interaction is anti-bonding. The ligands at equatorial positions have same types MOs.


Overall MO bonding is bonding character. The in-ligand bonding of four ligands is pi-antibonding. Along z-direction, in-ligand bonding is pi-antibonding.



[Ti(CO)6]2-


Cr(CO)6



Summary table

bond length (Cr-C) = 1.915 Å

         Item               Value     Threshold  Converged?
 Maximum Force            0.000110     0.000450     YES
 RMS     Force            0.000041     0.000300     YES
 Maximum Displacement     0.000709     0.001800     YES
 RMS     Displacement     0.000336     0.001200     YES

vibrational frequencies:

Low frequencies ---   -0.0006   -0.0003    0.0007   11.7424   11.7424   11.7424
Low frequencies ---   66.6546   66.6547   66.6547

Frequency analysis log file CRCO_GEN_OPT_FREQ.LOG



Cr(CO)6


[Fe(CO)6]2+


Summary table

bond length (Fe-C) = 2.136 Å


         Item               Value     Threshold  Converged?
 Maximum Force            0.000175     0.000450     YES
 RMS     Force            0.000039     0.000300     YES
 Maximum Displacement     0.000494     0.001800     YES
 RMS     Displacement     0.000138     0.001200     YES


vibrational frequencies

Low frequencies --- -572.6144 -572.6144 -387.4436 -340.7770 -323.3723 -289.6696
Low frequencies --- -289.6696 -249.5631 -105.2159

Frequency analysis log file FECO_GEN_OPT_FREQ.LOG


[Fe(CO)6]2+

Main group halides

RB3LYP/Gen


isomer (a)

relative energy = -2352.40631 a.u. = 6.17624277*10^6 kJ/mol



         Item               Value     Threshold  Converged?
 Maximum Force            0.000002     0.000450     YES
 RMS     Force            0.000001     0.000300     YES
 Maximum Displacement     0.000642     0.001800     YES
 RMS     Displacement     0.000255     0.001200     YES
 Low frequencies ---   -5.1634   -5.0501   -3.1849    0.0022    0.0028    0.0041
 Low frequencies ---   14.8310   63.2729   86.0759

Frequency analysis log file AL_GEN_OPT_FREQ.LOG