SeyedAbdolreza Sadjadi
December 17, 2015
Laboratory for Space Research (LSR)
The University of Hong Kong ssadjadi@hku.hk
http://www.scifac.hku.hk/kwok/sal/abdi.html
11 th Pacific Rim Conference on Stellar Astrophysics

modeling prediction
PES calculations interpretation simulation
11 th Pacific Rim Conference on Stellar Astrophysics

700
600
500
400
300
200
100
2
HD44179
3.30
4
6.27
6
7.87
8.66
observations and proposed models
3.29
11.25
8 10 12 wavelenght (µm)
14 16 18 20
6.22
3.39
NGC7027
6.98
7.32
7.65
7.9
8.6
11 th Pacific Rim Conference on Stellar Astrophysics

calculated geometry of C
155
H
240
B3LYP/PC1 (extra care on polarization effects)
30 CPUs , 20 days
Kwok and Zhang, Nature, 479:80 (2011)
Sadjadi, Zhang and Kwok, ApJ, 807:95 (2015 July 1)
11 th Pacific Rim Conference on Stellar Astrophysics

simulated IR spectra for C
155
H
240
, DFT/Drude, T=500 K
1000
900 NGC7027
800
700
600
500
6.94
400
13.19
300
7.37
200
100
3.4
6.35
8.24 9.26
9.78 11.16
15.83
19.03
0
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 wavelenght (µm)
Sadjadi , Zhang and Kwok, ApJ, 807:95 (2015 July 1)
11 th Pacific Rim Conference on Stellar Astrophysics

2.5
2.0
1.5
1.0
0.5
0.0
2 simulated IR spectra for 40 MAONs, DFT/Drude, T=500 K
4.0
3.5
3.0
4 6 8 10 12 wavelength (µm)
14 16 18
Sadjadi, Zhang and Kwok, ApJ, 807:95 (2015 July 1)
20
11 th Pacific Rim Conference on Stellar Astrophysics

12
10
8
6
4
2
0
2
20 simulated IR spectra for 60 PAHs, DFT/Drude, T=500 K
18
16
14
4 6 8 10 12 14 16 18 wavelength (µm)
Sadjadi, Zhang and Kwok, ApJ, 807:95 (2015 July 1)
20
Annual meeting of the Hong Kong Astrophysical Society

Vibrational Self-Consistent Field (VSCF) calculations perturbation theory, MP2/DZ or TZ water molecule
7524 (O_F3) strong
7524 (F2+F3) very weak
1629(F1)
7377(O_F2) 5435 (F1+F3)
5322(F1+F2)
3823(F3)
3731(F2)
3240 (O_F1)
(cm -1 )
Annual meeting of the Hong Kong Astrophysical Society

C
155
H
240
(vibrational motion at 3.4 µm)
3.29
NGC7027
3.39
asymmetric methylene C-H stretching
11 th Pacific Rim Conference on Stellar Astrophysics

C
155
H
240
(vibrational motion at 6.35 µm)
6.22
6.98
7.32
7.65
7.9
NGC7027
8.6
aromatic C-C stretching coupled with
C-H in plane bending
11 th Pacific Rim Conference on Stellar Astrophysics

C
155
H
240
(vibrational motion at 8.13 µm)
6.22
6.98
7.32
7.65
7.9
NGC7027
8.6
methylene wagging
Annual meeting of the Hong Kong Astrophysical Society

C
155
H
240
(vibrational motion at 11.16 µm)
NGC7027
11.24
12.8
13.5
13.1
aromatic C-H, OOP coupled with
Methyl & methylene vibrations
11 th Pacific Rim Conference on Stellar Astrophysics

C
155
H
240
(vibrational motion at 13.20 µm)
NGC7027
11.24
12.8
13.5
13.1
aromatic C-H, OOP
11 th Pacific Rim Conference on Stellar Astrophysics

C
155
H
240
(vibrational motion at 19.06 µm : 32% aromatic, 68% aliphatic)
NGC7027
11.24
12.8
13.5
13.1
complex vibrations
11 th Pacific Rim Conference on Stellar Astrophysics

1945
Displacement
Vector
Analysis
Molecular
Mechanics force field
Quantum
Mechanics
𝐻Ψ = 𝐸Ψ
𝐼
𝐶𝐴𝑅𝑇 𝑘,𝑖
3𝑁
=
𝐷 𝑘,𝑗
𝐿 𝑗,𝑖 𝑚 𝑘 𝑗
3𝑁
𝑁 𝑖
= ( (𝐼
𝐶𝐴𝑅𝑇 𝑘,𝑖
) 2 ) −1 𝑘
11 th Pacific Rim Conference on Stellar Astrophysics

solo
60 neutral honeycomb like PAH duet
10.0 10.5 11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0
100
75 solo
50
25
75 duet
50
25
75 trio
50
25
75 quarto
50
25
0
10.0 10.5 11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0
wavelength (µm)
Sadjadi, Zhang and Kwok, ApJ, 807:95 (2015 July 1)
11 th Pacific Rim Conference on Stellar Astrophysics

Tabulated band positions Spectra database
(250,000 Molecule)
Intellectual finding of complex relationships between any kinds of spectroscopic properties and molecular specifications
All these approaches are followed in our Lab
11 th Pacific Rim Conference on Stellar Astrophysics

DFT broadening vibrational analysis fingerprint
Sadjadi, Zhang and Kwok, ApJ, 801:34 (2015 March 1)
11 th Pacific Rim Conference on Stellar Astrophysics

molecule
CQC spectra forward transformation of molecule(s) to the spectra
CQC ?
molecule backward transformation of spectra to its molecular origin
11 th Pacific Rim Conference on Stellar Astrophysics

• I am grateful to my supervisor:
Professor Sun Kwok my two colleagues:
Dr. Yong Zhang Dr. Chih-Hao Hsia
• Professor Quentin Parker’s group and all other colleagues in our LSR
• My colleagues in Chemistry Department (Professor G.H.Chen’s group)
11 th Pacific Rim Conference on Stellar Astrophysics