Calculate the structures and atomization energies (AE) of the following molecules with the following methods then compare with the experimental values

molecular : H₂、Li₂、B₂、C_2、N₂、O₂、F₂、P₂、S₂、Cl₂

• Calculate the atomization energies by calculating A & A₂ in Gaussian.
• Calculate the atomization energies (AE) by following methods/basis set

         MP2/6-31+G(d,p)

         B3LYP/aug-cc-pVTZ

       

Collect all data from the output file and use the function 2*A(EE)-A₂(EE)*627.5095 kcal/mole

Step1

Step2

Step3

Step4

( kcal/mol )

Atomization energies of diatomic compound
	MP2/6-31+G(d,p)	B3LYP/aug-cc-pVTZ	Exp( De )
H2	101.2	110.1	109.5
Li2	14.3	20.9	24.6
B2	29.8	34.4	67.1
C2	91.1	103.7	145.7
N2	215.6	228.9	228.5
O2	86.8	84.7	120
F2	34.8	37.1	38.2
P2	93.7	114.1	117.1
S2	63.9	78.3	101.7
Cl2	41.9	54	58

 

Atomization energies of diatomic compound
	MP2/6-31+G(d,p)	B3LYP/aug-cc-pVTZ
H2	8.3	0.6
Li2	10.3	3.7
B2	37.3	32.7
C2	54.6	42
N2	12.9	0.4
O2	33.2	35.3
F2	3.4	1.1
P2	23.4	3
S2	37.8	23.4
Cl2	16.1	4
絕對誤差平均值	23.7	14.6

 

Calculate the standard enthalpy of formation (ΔH°f) of AHn (A = H~Ne) with following methods then compare with the experimental values.

• Calculate the atomization energies by calculating A & AH_n in Gaussian.
• Collect all data from the output file and use the function -Δ[H°_f (AH_n)]=TAE_B.O (LiH)+ E_thermal (A)+ E_thermal (H)-[ ZPE(AH_n)+E_thermal (AH_n)]+ XRT – [ΔH°_f(H)+ΔH°_f(A)] to calculate the total atomization energies (TAE).
• Find the ΔH°_f(H) & other elements in the Computational Chemistry Comparison and Benchmark DataBase

 

Atomization energies of hydrides
	MP2/aug-cc-pVTZ	Experimental value
H2	6	0
LiH	39.6	33.6
BeH2	41.6	30
BH3	29.1	21
CH4	-8	-17.8
NH3	-2.7	-11
H2O	-57.1	-57.8
HF	-67.6	-65.3