國立高雄大學圖資館 |

Language: English

Back

Electronic absorption spectra from f...

Hazra, Anirban.

Electronic absorption spectra from first principles.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Electronic absorption spectra from first principles.
Author:	Hazra, Anirban.
Description:	167 p.
Notes:	Adviser: Marcel Nooijen.
Notes:	Source: Dissertation Abstracts International, Volume: 66-01, Section: B, page: 0296.
Contained By:	Dissertation Abstracts International66-01B.
Subject:	Chemistry, Physical.
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3162767
ISBN:	049696514X

Electronic absorption spectra from first principles.
Hazra, Anirban.

Electronic absorption spectra from first principles. - 167 p.

Adviser: Marcel Nooijen.

Thesis (Ph.D.)--Princeton University, 2005.

A method called vertical FC is proposed, where in accord with the short-time picture of molecular spectroscopy, the approximate excited-state potential energy surface that is used to calculate the electronic spectrum is taken to reproduce the ab initio potential at the ground-state equilibrium geometry. The potential energy surface along normal modes may be treated either in the harmonic approximation or using the full one-dimensional potential. Systems with highly anharmonic potential surfaces can be treated and expensive geometry optimizations are not required, unlike the traditional FC approach. The ultraviolet spectrum of ethylene between 6.2 and 8.7 eV is simulated using vertical FC.

ISBN: 049696514XSubjects--Topical Terms:

226924
Chemistry, Physical.

Electronic absorption spectra from first principles.
LDR:03456nmm _2200313 _450 001 167318
005 20061005085853.5
008 090528s2005 eng d
020 $a 049696514X
035 $a 00197934
040 $a UnM $c UnM
100 0 $a Hazra, Anirban. $3 237464
245 1 0 $a Electronic absorption spectra from first principles.
300 $a 167 p.
500 $a Adviser: Marcel Nooijen.
500 $a Source: Dissertation Abstracts International, Volume: 66-01, Section: B, page: 0296.
502 $a Thesis (Ph.D.)--Princeton University, 2005.
520 # $a A method called vertical FC is proposed, where in accord with the short-time picture of molecular spectroscopy, the approximate excited-state potential energy surface that is used to calculate the electronic spectrum is taken to reproduce the ab initio potential at the ground-state equilibrium geometry. The potential energy surface along normal modes may be treated either in the harmonic approximation or using the full one-dimensional potential. Systems with highly anharmonic potential surfaces can be treated and expensive geometry optimizations are not required, unlike the traditional FC approach. The ultraviolet spectrum of ethylene between 6.2 and 8.7 eV is simulated using vertical FC.
520 # $a Methods for simulating electronic absorption spectra of molecules from first principles (i.e., without any experimental input, using quantum mechanics) are developed and compared. The electronic excitation and photoelectron spectra of ethylene are simulated, using the EOM-CCSD method for the electronic structure calculations.
520 # $a The different approaches for simulating spectra are broadly of two types---Frank-Condon (FC) approaches and vibronic coupling approaches. For treating the vibrational motion, the former use the Born-Oppenheimer or single surface approximation while the latter do not. Moreover, in our FC approaches the vibrational Hamiltonian is additively separable along normal mode coordinates, while in vibronic approaches a model Hamiltonian (obtained from ab initio electronic structure theory) provides an intricate coupling between both normal modes and electronic states.
520 # $a The photoelectron spectrum corresponding to the four lowest ionized states of ethylene are simulated using various methods. For the ground ionized state, Duschinsky rotation among the symmetric normal modes is found to play an important role. The FC and vibronic models are refined to capture this effect by locating the center of the Taylor expansion of the potential surfaces used in the models to be the symmetry constrained optimized geometry of the ionized state.
520 # $a While FC approaches for simulation are computationally very efficient, they are not accurate when the underlying approximations are unreasonable. Then, vibronic coupling model Hamiltonians are necessary. Since these Hamiltonians have an analytic form, they are used to map the potential energy surfaces and understand their topology. Spectra are obtained by numerical diagonalization of the Hamiltonians.
590 $a School code: 0181.
650 # 0 $a Chemistry, Physical. $3 226924
650 # 0 $a Physics, Molecular. $3 227726
690 $a 0494
690 $a 0609
710 0 # $a Princeton University. $3 212488
773 0 # $g 66-01B. $t Dissertation Abstracts International
790 $a 0181
790 1 0 $a Nooijen, Marcel, $e advisor
791 $a Ph.D.
792 $a 2005
856 4 0 $u http://libsw.nuk.edu.tw:81/login?url=http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3162767 $z http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3162767