Band
Title
8782.0 cm-1: ν2+2ν34 of 12CH4 in natural CH4 - phase I
Type
absorption
Assignments summary
Assignment Symmetry Mode Specie(s) Molecule/Atom Bond Multiplicity Degeneracy Contribution Resonance
ν2+2ν34 combination vibration 12CH4 CH4 12C-1H
12C-1H
12C-1H
unknown
Characteristics summary
Peak position
(cm-1)
Center position
(cm-1)
Width
(cm-1)
Shape Asymmetry factor Peak intensity
(cm-1)
Peak intensity relative Peak strength Integrated intensity
(cm-2)
Integrated intensity relative Integrated strength Temperature
(K)
Pressure
(bar)
8782 ± 1 - - asymmetric 2.59 ± 0.05 3.237e-04 w 30.0
8782 ± 2 - - asymmetric 1.29 ± 0.03 w 90.0 0.117
Label
ν2+2ν34
Category
combination vibration

Evaluation

Level
fully assigned
Evaluation
validated
# Multiplicity type Degeneracy Other band
1 unknown

Vibration modes

Label (type)
ν2 (deformation)       Bond: 12C-1H
3 (stretching asym.)       Bond: 12C-1H
ν4 (deformation)       Bond: 12C-1H
Texture
crystal

Temperature

Temperature
30.0 ± 1.0 K
Formation temperature
90.7 K
Temperature max
90.7 K
Method #1
spectrum measurement
Overlap
moderately blended
Peak
8782 ± 1 cm-1 (peak)
Evaluation
validated
Quality
B
Shape
asymmetric
Evaluation
undefined
Comments
may contain a weaker mode in its high frequency wing as a broad shoulder around 8805 cm-1
Method
peak intensity
Absorption coefficient
2.59 ± 0.05 cm-1
Relative intensity
3.237e-04 ± 6.25e-06
Strength
weak (w)
Evaluation
validated
Quality
A
Texture
crystal

Temperature

Temperature
90.0 ± 1.0 K
Formation temperature
90.7 K
Temperature max
90.7 K

Pressure

Pressure
0.117 bar
Comments
Vapor pressure
Method #1
spectrum measurement
Overlap
moderately blended
Peak
8782 ± 2 cm-1 (peak)
Evaluation
validated
Quality
B
Shape
asymmetric
Evaluation
undefined
Comments
other weaker modesaround 8760 and 8805 cm-1 and are merged in both wings
Method
peak intensity
Absorption coefficient
1.29 ± 0.03 cm-1
Strength
weak (w)
Evaluation
validated
Quality
B