	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: HSEh1PBE/6-31+G**

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 HSEh1PBE/6-31+G**

	hartrees
Energy at 0K	-581.066459
Energy at 298.15K
HF Energy	-581.066459
Nuclear repulsion energy	78.797325

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 HSEh1PBE/6-31+G**

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	2279	2176	0.00	421.27	0.19	0.32
2	A_g	943	900	0.00	22.47	0.23	0.37
3	A_g	596	569	0.00	106.43	0.20	0.33
4	A_u	545	521	0.00	0.00	0.00	0.00
5	B_1u	2273	2170	76.40	0.00	0.00	0.00
6	B_1u	861	822	106.80	0.00	0.00	0.00
7	B_2g	220i	210i	0.00	44.12	0.75	0.86
8	B_2u	2309	2205	138.91	0.00	0.00	0.00
9	B_2u	352	336	16.47	0.00	0.00	0.00
10	B_3g	2300	2196	0.00	227.61	0.75	0.86
11	B_3g	598	571	0.00	7.00	0.75	0.86
12	B_3u	520	496	0.50	0.00	0.00	0.00

Unscaled Zero Point Vibrational Energy (zpe) 6678.0 cm^-1
Scaled (by 0.9548) Zero Point Vibrational Energy (zpe) 6376.2 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 HSEh1PBE/6-31+G**

A	B	C
2.65655	0.21672	0.20037

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

Geometric Data calculated at HSEh1PBE/6-31+G**

Point Group is D_2h

Cartesians (Å)

Atom	y (Å)	z (Å)
Si1	0.000	1.069
Si2	0.000	-1.069
H3	1.255	1.854
H4	-1.255	1.854
H5	1.255	-1.854
H6	-1.255	-1.854

Atom - Atom Distances (Å)

	Si1	Si2	H3	H4	H5	H6
Si1		2.1377	1.4802	1.4802	3.1811	3.1811
Si2	2.1377		3.1811	3.1811	1.4802	1.4802
H3	1.4802	3.1811		2.5093	3.7087	4.4778
H4	1.4802	3.1811	2.5093		4.4778	3.7087
H5	3.1811	1.4802	3.7087	4.4778		2.5093
H6	3.1811	1.4802	4.4778	3.7087	2.5093

picture of Disilene state 1 conformation 1

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
Si1	Si2	H5	122.050	Si1	Si2	H6	122.050
Si2	Si1	H3	122.050	Si2	Si1	H4	122.050
H3	Si1	H4	115.900	H5	Si2	H6	115.900

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at HSEh1PBE/6-31+G** Charges (e)

Number	Element	Mulliken
1	Si	0.087
2	Si	0.087
3	H	-0.044
4	H	-0.044
5	H	-0.044
6	H	-0.044

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	-31.943	0.000	0.000
y	0.000	-29.039	0.000
z	0.000	0.000	-27.590

Traceless
	x	y	z
x	-3.628	0.000	0.000
y	0.000	0.727	0.000
z	0.000	0.000	2.901

Polar
3z²-r²	5.802
x²-y²	-2.904
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	7.161	0.000	0.000
y	0.000	6.782	0.000
z	0.000	0.000	14.790

<r²> (average value of r²) Å²

<r²>	70.480
(<r²>)^1/2	8.395

Conformer 2 (C2H)

Jump to S1C1 S1C3

Energy calculated at HSEh1PBE/6-31+G**

	hartrees
Energy at 0K	-581.067288
Energy at 298.15K
HF Energy	-581.067288
Nuclear repulsion energy	78.223377

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 HSEh1PBE/6-31+G**

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	2256	2154	0.00	432.18	0.19	0.32
2	A_g	947	905	0.00	35.65	0.25	0.40
3	A_g	575	549	0.00	82.87	0.25	0.40
4	A_g	296	283	0.00	32.60	0.38	0.55
5	A_u	2285	2182	167.45	0.00	0.00	0.00
6	A_u	532	508	0.28	0.00	0.00	0.00
7	A_u	343	328	16.84	0.00	0.00	0.00
8	B_g	2274	2171	0.00	261.86	0.75	0.86
9	B_g	611	583	0.00	8.89	0.75	0.86
10	B_u	2251	2149	119.92	0.00	0.00	0.00
11	B_u	904	863	161.06	0.00	0.00	0.00
12	B_u	455	435	27.10	0.00	0.00	0.00

Unscaled Zero Point Vibrational Energy (zpe) 6864.2 cm^-1
Scaled (by 0.9548) Zero Point Vibrational Energy (zpe) 6553.9 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 HSEh1PBE/6-31+G**

A	B	C
2.52613	0.21286	0.19867

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

Geometric Data calculated at HSEh1PBE/6-31+G**

Point Group is C_2h

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
Si1	0.000	1.081	0.000
Si2	0.000	-1.081	0.000
H3	0.389	1.806	1.237
H4	0.389	1.806	-1.237
H5	-0.389	-1.806	1.237
H6	-0.389	-1.806	-1.237

Atom - Atom Distances (Å)

	Si1	Si2	H3	H4	H5	H6
Si1		2.1629	1.4851	1.4851	3.1650	3.1650
Si2	2.1629		3.1650	3.1650	1.4851	1.4851
H3	1.4851	3.1650		2.4734	3.6945	4.4461
H4	1.4851	3.1650	2.4734		4.4461	3.6945
H5	3.1650	1.4851	3.6945	4.4461		2.4734
H6	3.1650	1.4851	4.4461	3.6945	2.4734

picture of Disilene state 1 conformation 2

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
Si1	Si2	H5	119.194	Si1	Si2	H6	119.194
Si2	Si1	H3	119.194	Si2	Si1	H4	119.194
H3	Si1	H4	112.761	H5	Si2	H6	112.761

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at HSEh1PBE/6-31+G** Charges (e)

Number	Element	Mulliken
1	Si	0.098
2	Si	0.098
3	H	-0.049
4	H	-0.049
5	H	-0.049
6	H	-0.049

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	-31.740	-0.252	0.000
y	-0.252	-27.739	0.000
z	0.000	0.000	-29.317

Traceless
	x	y	z
x	-3.212	-0.252	0.000
y	-0.252	2.790	0.000
z	0.000	0.000	0.422

Polar
3z²-r²	0.844
x²-y²	-4.001
xy	-0.252
xz	0.000
yz	0.000

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

	x	y	z
x	7.151	-0.621	0.000
y	-0.621	15.017	0.000
z	0.000	0.000	7.224

<r²> (average value of r²) Å²

<r²>	71.000
(<r²>)^1/2	8.426

Conformer 3 (C2V)

Jump to S1C1 S1C2

Energy calculated at HSEh1PBE/6-31+G**

	hartrees
Energy at 0K	-581.028538
Energy at 298.15K
HF Energy	-581.028538
Nuclear repulsion energy	73.109254

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 HSEh1PBE/6-31+G**

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	2109	2014	417.90	296.53	0.40	0.57
2	A₁	1665	1589	0.06	73.15	0.12	0.21
3	A₁	887	847	39.59	118.84	0.33	0.50
4	A₁	408	390	1.37	65.27	0.41	0.58
5	A₁	379	362	0.57	5.18	0.11	0.19
6	A₂	1416	1352	0.00	0.13	0.75	0.86
7	A₂	638	610	0.00	0.36	0.75	0.86
8	B₁	1337	1276	41.15	0.05	0.75	0.86
9	B₁	841	803	12.93	23.64	0.75	0.86
10	B₂	2081	1987	12.82	18.85	0.75	0.86
11	B₂	1387	1324	1145.09	22.40	0.75	0.86
12	B₂	729	696	79.11	15.59	0.75	0.86

Unscaled Zero Point Vibrational Energy (zpe) 6938.6 cm^-1
Scaled (by 0.9548) Zero Point Vibrational Energy (zpe) 6625.0 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 HSEh1PBE/6-31+G**

A	B	C
2.52119	0.16455	0.16081

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

Geometric Data calculated at HSEh1PBE/6-31+G**

Point Group is C_2v

Cartesians (Å)

Atom	x (Å)	y (Å)	z (Å)
Si1	0.000	1.315	-0.089
Si2	0.000	-1.315	-0.089
H3	-1.034	0.000	-0.182
H4	1.034	0.000	-0.182
H5	0.000	1.322	1.430
H6	0.000	-1.322	1.430

Atom - Atom Distances (Å)

	Si1	Si2	H3	H4	H5	H6
Si1		2.6302	1.6752	1.6752	1.5195	3.0433
Si2	2.6302		1.6752	1.6752	3.0433	1.5195
H3	1.6752	1.6752		2.0671	2.3268	2.3268
H4	1.6752	1.6752	2.0671		2.3268	2.3268
H5	1.5195	3.0433	2.3268	2.3268		2.6435
H6	3.0433	1.5195	2.3268	2.3268	2.6435

picture of Disilene state 1 conformation 3

More geometry information
Calculated Bond Angles

atom1	atom2	atom3	angle	atom1	atom2	atom3	angle
Si1	Si2	H5	29.953	Si1	Si2	H6	90.250
Si2	Si1	H3	38.276	Si2	Si1	H4	38.276
H3	Si1	H4	76.192	H5	Si2	H6	60.297

Electronic energy levels

Charges, Dipole, Quadrupole and Polarizability
Charges from optimized geometry at HSEh1PBE/6-31+G** Charges (e)

Number	Element	Mulliken
1	Si	0.223
2	Si	0.223
3	H	-0.144
4	H	-0.144
5	H	-0.079
6	H	-0.079

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	0.847	0.847
CHELPG
AIM
ESP

Electric Quadrupole moment
Quadrupole components in D Å

Primitive
	x	y	z
x	-27.265	0.000	0.000
y	0.000	-32.881	0.000
z	0.000	0.000	-33.587

Traceless
	x	y	z
x	5.970	0.000	0.000
y	0.000	-2.456	0.000
z	0.000	0.000	-3.514

Polar
3z²-r²	-7.028
x²-y²	5.617
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	6.344	0.000	0.000
y	0.000	13.252	0.000
z	0.000	0.000	8.246

<r²> (average value of r²) Å²

<r²>	77.951
(<r²>)^1/2	8.829

All results from a given calculation for Si2H4 (Disilene)

using model chemistry: HSEh1PBE/6-31+G**

States and conformations

Conformer 1 (D2H)

Conformer 2 (C2H)

Conformer 3 (C2V)

All results from a given calculation for Si₂H₄ (Disilene)