Theoretical Level Dependency:
Inversion Barrier of Ammonia

Sundeep Rayat




Experimental value for the inversion of ammonia = 5.8 Kcal/mole

METHOD FILE E(total)
C3v
[Hartrees]
Nimg
C3v
FILE E(total)
D3h
[Hartrees]
Nimg
D2h
Activation Barrier
[Kcal /mole]
CNDO amm_cndo.log -13.889753 0 ammt_cndo.log -13.864334 1 15.95
MNDO amm_mndo.log -0.009676 0 ammt_mndo.log 0.008794 1 11.59
AM1 amm_am1.log -0.011635 0 ammt_am1.log -0.004875 1 4.24
PM3 amm_pm3.log -0.004908 0 ammt_pm3.log 0.011003 1 9.98
RHF/STO-3G amm_min.log -55.45542 0 ammt_min.log -55.437665 1 11.14
RHF/STO-3G amm_min.log -55.45542 0 ammt_min.log -55.437665 1 11.14
RHF/3-21G amm_3-21.log -55.872203 0 ammt_3-21.log -55.869642 1 1.61
RHF/6-31G amm_6-31.log -56.165521 0 ammt_6-31.log -56.164926 1 0.37
RHF/6-31G* amm_6-31D.log -56.184356 0 ammt_6-31D.log -56.173985 1 6.51
RHF/6-31G** amm6-31DD.log -56.195545 0 ammt6-31DD.log -56.186762 1 5.51
RHF/cc-pVDZ amm_cc-pVDZ.log -56.195732 0 ammt_cc-pVDZ.log -56.184243 1 7.21
RHF/cc-pVTZ amm_cc-pVTZ.log -56.218290 0 ammt_cc-pVTZ.log -56.209747 1 5.36
RHF/cc-pVQZ amm_cc-pVQZ.log -56.223596 0 ammt_cc-pVQZ.log -56.215525 1 5.06
MP2(full)/6-31G* amm_mp6-31(d).log 0 ammt_mp6-31(d).log 1
MP3(full)/6-31G* amm_mp6-31(d).log 0 ammt_mp6-31(d).log 1
MP4(full)/6-31G* amm_mp6-31(d).log 0 ammt_mp6-31(d).log 1
MP2(full)/6-31G** amm_mp6-31(df).log 0 ammt_mp6-31(df).log 1
MP3(full)/6-31G** amm_mp6-31(df).log 0 ammt_mp6-31(df).log 1
MP4(full)/6-31G** amm_mp6-31(df).log 0 ammt_mp6-31(df).log 1
(a) The MPx calculations all are based on the RHF/cc-pVQZ structures.