	Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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All results from a given calculation for Si₂H₄ (Disilene)

using model chemistry: B2PLYP/6-311+G(3df,2p)

19 10 17 12 22

States and conformations

State	Conformation	minimum conformation	conformer description	state description
1	1	no	D2H	¹A_G
1	2	yes	C2H	¹A_G
1	3	no	C2V	¹A₁

Conformer 1 (D2H)

Jump to S1C2 S1C3

Energy calculated at B2PLYP/6-311+G(3df,2p)

	hartrees
Energy at 0K	-581.083806
Energy at 298.15K
HF Energy	-581.002949
Nuclear repulsion energy	79.055722

The energy at 298.15K was derived from the energy at 0K and an integrated heat capacity that used the calculated vibrational frequencies.

Vibrational Frequencies calculated at B2PLYP/6-311+G(3df,2p)

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)	Raman Act (Å⁴/u)	Dep P	Dep U
1	A_g	2290	2290	0.00	376.01	0.14	0.25
2	A_g	959	959	0.00	19.26	0.11	0.20
3	A_g	594	594	0.00	110.51	0.15	0.26
4	A_u	552	552	0.00	0.00	0.00	0.00
5	B_1u	2283	2283	66.60	0.00	0.00	0.00
6	B_1u	879	879	116.29	0.00	0.00	0.00
7	B_2g	203i	203i	0.00	36.81	0.75	0.86
8	B_2u	2317	2317	94.89	0.00	0.00	0.00
9	B_2u	355	355	20.24	0.00	0.00	0.00
10	B_3g	2308	2308	0.00	198.95	0.75	0.86
11	B_3g	603	603	0.00	4.77	0.75	0.86
12	B_3u	533	533	0.25	0.00	0.00	0.00

Unscaled Zero Point Vibrational Energy (zpe) 6734.6 cm^-1
Scaled (by 1) Zero Point Vibrational Energy (zpe) 6734.6 cm^-1
See section III.C.1 List or set vibrational scaling factors to change the scale factors used here.
See section III.C.2 Calculate a vibrational scaling factor for a given set of molecules to determine the least squares best scaling factor.

Rotational Constants (cm^-1) from geometry optimized at B2PLYP/6-311+G(3df,2p)

A	B	C
2.70058	0.21754	0.20132

See section I.F.4 to change rotational constant units

Geometric Data calculated at B2PLYP/6-311+G(3df,2p)

Point Group is D_2h

Cartesians (Å)

Atom	y (Å)	z (Å)
Si1	0.000	1.067
Si2	0.000	-1.067
H3	1.244	1.850
H4	-1.244	1.850
H5	1.244	-1.850
H6	-1.244	-1.850

Atom - Atom Distances (Å)

	Si1	Si2	H3	H4	H5	H6
Si1		2.1339	1.4701	1.4701	3.1711	3.1711
Si2	2.1339		3.1711	3.1711	1.4701	1.4701
H3	1.4701	3.1711		2.4887	3.6996	4.4588
H4	1.4701	3.1711	2.4887		4.4588	3.6996
H5	3.1711	1.4701	3.6996	4.4588		2.4887
H6	3.1711	1.4701	4.4588	3.6996	2.4887

picture of Disilene state 1 conformation 1

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
Si1	Si2	H5	122.174	Si1	Si2	H6	122.174
Si2	Si1	H3	122.174	Si2	Si1	H4	122.174
H3	Si1	H4	115.652	H5	Si2	H6	115.652

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at B2PLYP/6-311+G(3df,2p) Charges (e)

Number	Element	Mulliken
1	Si	0.038
2	Si	0.038
3	H	-0.019
4	H	-0.019
5	H	-0.019
6	H	-0.019

Electric dipole moments
Electric dipole components in Debye
(What's a Debye? See section VII.A.3)

	x	y	z	Total
	0.000	0.000	0.000	0.000
CHELPG
AIM
ESP

Electric Quadrupole moment
Quadrupole components in D Å

Primitive
	x	y	z
x	-32.023	0.000	0.000
y	0.000	-29.469	0.000
z	0.000	0.000	-27.545

Traceless
	x	y	z
x	-3.516	0.000	0.000
y	0.000	0.315	0.000
z	0.000	0.000	3.201

Polar
3z²-r²	6.402
x²-y²	-2.554
xy	0.000
xz	0.000
yz	0.000

Polarizabilities
Components of the polarizability tensor.
Units are Å³ (Angstrom cubed)
Change units.

	x	y	z
x	9.157	0.000	0.000
y	0.000	8.260	0.000
z	0.000	0.000	14.691

<r²> (average value of r²) Å²

<r²>	70.293
(<r²>)^1/2	8.384

Conformer 2 (C2H)

Jump to S1C1 S1C3

Energy calculated at B2PLYP/6-311+G(3df,2p)

	hartrees
Energy at 0K	-581.084388
Energy at 298.15K
HF Energy	-581.002768
Nuclear repulsion energy	78.529563

The energy at 298.15K was derived from the energy at 0K and an integrated heat capacity that used the calculated vibrational frequencies.

Vibrational Frequencies calculated at B2PLYP/6-311+G(3df,2p)

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)	Raman Act (Å⁴/u)	Dep P	Dep U
1	A_g	2267	2267	0.00	402.28	0.16	0.27
2	A_g	962	962	0.00	20.01	0.18	0.31
3	A_g	575	575	0.00	88.20	0.15	0.26
4	A_g	273	273	0.00	23.91	0.54	0.70
5	A_u	2293	2293	118.35	0.00	0.00	0.00
6	A_u	536	536	0.05	0.00	0.00	0.00
7	A_u	347	347	18.47	0.00	0.00	0.00
8	B_g	2283	2283	0.00	222.64	0.75	0.86
9	B_g	612	612	0.00	4.10	0.75	0.86
10	B_u	2262	2262	98.92	0.00	0.00	0.00
11	B_u	917	917	163.03	0.00	0.00	0.00
12	B_u	472	472	21.73	0.00	0.00	0.00

Unscaled Zero Point Vibrational Energy (zpe) 6900.7 cm^-1
Scaled (by 1) Zero Point Vibrational Energy (zpe) 6900.7 cm^-1
See section III.C.1 List or set vibrational scaling factors to change the scale factors used here.
See section III.C.2 Calculate a vibrational scaling factor for a given set of molecules to determine the least squares best scaling factor.

Rotational Constants (cm^-1) from geometry optimized at B2PLYP/6-311+G(3df,2p)

A	B	C
2.58396	0.21402	0.19963

See section I.F.4 to change rotational constant units

Geometric Data calculated at B2PLYP/6-311+G(3df,2p)

Point Group is C_2h

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
Si1	0.000	1.078	0.000
Si2	0.000	-1.078	0.000
H3	0.355	1.809	1.230
H4	0.355	1.809	-1.230
H5	-0.355	-1.809	1.230
H6	-0.355	-1.809	-1.230

Atom - Atom Distances (Å)

	Si1	Si2	H3	H4	H5	H6
Si1		2.1567	1.4743	1.4743	3.1586	3.1586
Si2	2.1567		3.1586	3.1586	1.4743	1.4743
H3	1.4743	3.1586		2.4604	3.6873	4.4328
H4	1.4743	3.1586	2.4604		4.4328	3.6873
H5	3.1586	1.4743	3.6873	4.4328		2.4604
H6	3.1586	1.4743	4.4328	3.6873	2.4604

picture of Disilene state 1 conformation 2

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
Si1	Si2	H5	119.710	Si1	Si2	H6	119.710
Si2	Si1	H3	119.710	Si2	Si1	H4	119.710
H3	Si1	H4	113.110	H5	Si2	H6	113.110

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at B2PLYP/6-311+G(3df,2p) Charges (e)

Number	Element	Mulliken
1	Si	0.055
2	Si	0.055
3	H	-0.028
4	H	-0.028
5	H	-0.028
6	H	-0.028

Electric dipole moments
Electric dipole components in Debye
(What's a Debye? See section VII.A.3)

	x	y	z	Total
	0.000	0.000	0.000	0.000
CHELPG
AIM
ESP

Electric Quadrupole moment
Quadrupole components in D Å

Primitive
	x	y	z
x	-31.851	-0.362	0.000
y	-0.362	-27.719	0.000
z	0.000	0.000	-29.709

Traceless
	x	y	z
x	-3.137	-0.362	0.000
y	-0.362	3.060	0.000
z	0.000	0.000	0.076

Polar
3z²-r²	0.153
x²-y²	-4.131
xy	-0.362
xz	0.000
yz	0.000

Polarizabilities
Components of the polarizability tensor.
Units are Å³ (Angstrom cubed)
Change units.

	x	y	z
x	9.012	-0.544	0.000
y	-0.544	15.028	0.000
z	0.000	0.000	8.380

<r²> (average value of r²) Å²

<r²>	70.796
(<r²>)^1/2	8.414

Conformer 3 (C2V)

Jump to S1C1 S1C2

Energy calculated at B2PLYP/6-311+G(3df,2p)

	hartrees
Energy at 0K	-581.047393
Energy at 298.15K
HF Energy	-580.966161
Nuclear repulsion energy	73.439994

The energy at 298.15K was derived from the energy at 0K and an integrated heat capacity that used the calculated vibrational frequencies.

Vibrational Frequencies calculated at B2PLYP/6-311+G(3df,2p)

Mode Number	Symmetry	Frequency (cm^-1)	Scaled Frequency (cm^-1)	IR Intensities (km mol^-1)	Raman Act (Å⁴/u)	Dep P	Dep U
1	A₁	2117	2117	327.24	266.49	0.29	0.45
2	A₁	1650	1650	0.22	66.83	0.08	0.15
3	A₁	893	893	29.25	61.06	0.21	0.35
4	A₁	389	389	1.03	28.46	0.19	0.33
5	A₁	374	374	0.24	23.89	0.49	0.65
6	A₂	1396	1396	0.00	0.01	0.75	0.86
7	A₂	641	641	0.00	0.17	0.75	0.86
8	B₁	1300	1300	24.43	0.24	0.75	0.86
9	B₁	849	849	17.13	3.95	0.75	0.86
10	B₂	2092	2092	16.76	36.46	0.75	0.86
11	B₂	1404	1404	1160.59	25.36	0.75	0.86
12	B₂	744	744	94.37	0.03	0.75	0.86

Unscaled Zero Point Vibrational Energy (zpe) 6923.6 cm^-1
Scaled (by 1) Zero Point Vibrational Energy (zpe) 6923.6 cm^-1
See section III.C.1 List or set vibrational scaling factors to change the scale factors used here.
See section III.C.2 Calculate a vibrational scaling factor for a given set of molecules to determine the least squares best scaling factor.

Rotational Constants (cm^-1) from geometry optimized at B2PLYP/6-311+G(3df,2p)

A	B	C
2.56605	0.16566	0.16198

See section I.F.4 to change rotational constant units

Geometric Data calculated at B2PLYP/6-311+G(3df,2p)

Point Group is C_2v

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
Si1	0.000	1.310	-0.091
Si2	0.000	-1.310	-0.091
H3	-1.028	0.000	-0.138
H4	1.028	0.000	-0.138
H5	0.000	1.350	1.416
H6	0.000	-1.350	1.416

Atom - Atom Distances (Å)

	Si1	Si2	H3	H4	H5	H6
Si1		2.6191	1.6655	1.6655	1.5078	3.0572
Si2	2.6191		1.6655	1.6655	3.0572	1.5078
H3	1.6655	1.6655		2.0561	2.3012	2.3012
H4	1.6655	1.6655	2.0561		2.3012	2.3012
H5	1.5078	3.0572	2.3012	2.3012		2.7006
H6	3.0572	1.5078	2.3012	2.3012	2.7006

picture of Disilene state 1 conformation 3

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
Si1	Si2	H5	29.539	Si1	Si2	H6	91.549
Si2	Si1	H3	38.163	Si2	Si1	H4	38.163
H3	Si1	H4	76.232	H5	Si2	H6	62.010

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at B2PLYP/6-311+G(3df,2p) Charges (e)

Number	Element	Mulliken
1	Si	0.121
2	Si	0.121
3	H	-0.064
4	H	-0.064
5	H	-0.056
6	H	-0.056

Electric dipole moments
Electric dipole components in Debye
(What's a Debye? See section VII.A.3)

	x	y	z	Total
	0.000	0.000	0.495	0.495
CHELPG
AIM
ESP

Electric Quadrupole moment
Quadrupole components in D Å

Primitive
	x	y	z
x	-27.435	0.000	0.000
y	0.000	-32.167	0.000
z	0.000	0.000	-33.745

Traceless
	x	y	z
x	5.521	0.000	0.000
y	0.000	-1.577	0.000
z	0.000	0.000	-3.944

Polar
3z²-r²	-7.888
x²-y²	4.732
xy	0.000
xz	0.000
yz	0.000

Polarizabilities
Components of the polarizability tensor.
Units are Å³ (Angstrom cubed)
Change units.

	x	y	z
x	7.775	0.000	0.000
y	0.000	13.837	0.000
z	0.000	0.000	9.312

<r²> (average value of r²) Å²

<r²>	77.492
(<r²>)^1/2	8.803

All results from a given calculation for Si2H4 (Disilene)

using model chemistry: B2PLYP/6-311+G(3df,2p)

States and conformations

Conformer 1 (D2H)

Conformer 2 (C2H)

Conformer 3 (C2V)

All results from a given calculation for Si₂H₄ (Disilene)