Nadja Doslic - Academia.edu (original) (raw)

Papers by Nadja Doslic

Chemical Physics, 2003

... 10] to 4.6 kcal/mol using the PLAP1 correlation functional [8]. However, by using a sequence ... more ... 10] to 4.6 kcal/mol using the PLAP1 correlation functional [8]. However, by using a sequence of basis sets and employing several levels of electron correlation, Barone and Adamo [6] indicated ... A modified quadratic Shepard interpolation has been used to interpolate the 3D PESs ...

Journal of Physical Chemistry A, 2009

We consider the effect of isotopic labeling on the electric charge distribution and dynamics of t... more We consider the effect of isotopic labeling on the electric charge distribution and dynamics of the formic acid dimer. Our investigation is based on accurate ab initio calculations of vibrationally induced dipole moments and multidimensional quantum calculations of vibrational ground-state splittings. It is found that non-negligible dipole moments of µ ) 0.032 D and µ ) 0.021 D arise in HCOOH-DOOCD and HCOOH-DOOCH, respectively, suggesting the feasibility of microwave studies. Within the reaction surface Hamiltonian approach a ratio of splittings of 1:0.2:0.045 is predicted for HCOOH-HOOCH:HCOOH-DOOCH:HCOOD-DOOCH.

Physical Chemistry Chemical Physics, 2010

An extensive computational study of the conformational preferences of three capped dipeptides: Ac... more An extensive computational study of the conformational preferences of three capped dipeptides: Ac-Xxx-Phe-NH 2 , Xxx = Gly, Ala, Val is reported. On the basis of local second-order Møller-Plesset perturbation theory (LMP2) and DFT computations we were able to identify the experimentally observed conformers as g L -g L (gÀ) and b-turn I(g+) in Ac-Gly-Phe-NH 2 , and Ac-Ala-Phe-NH 2 , and as the closely related g L (g+)-g L (gÀ) and b-turn I(a,g+) in Ac-Val-Phe-NH 2 . In contrast to the experimental observation that peptides with bulky side chain have a propensity for b-turns, we show that in Ac-Val-Phe-NH 2 the minimum energy structure corresponds to the experimentally non detected b-strand.

European Physical Journal D, 1994

ABSTRACT

Physical Review A, 2005

State selective preparation and manipulation of discrete-level quantum systems such as atoms, mol... more State selective preparation and manipulation of discrete-level quantum systems such as atoms, molecules or quantum dots is the ultimate tool for many diverse fields such as laser control of chemical reactions, atom optics, high-precision metrology and quantum computing. Rabi oscillations are one of the simplest, yet potentially quite useful mechanisms for achieving such manipulation. Rabi theory establishes that in the two-level systems resonant drive leads to the periodic and complete population oscillations between the two system levels. In this paper an analytic optimization algorithm for producing Rabi-like oscillations in the general discrete many-level quantum system is presented.

Physical Review A, 2004

State selective preparation and manipulation of discrete-level quantum systems such as atoms, mol... more State selective preparation and manipulation of discrete-level quantum systems such as atoms, molecules or quantum dots is a the ultimate tool for many diverse fields such as laser control of chemical reactions, atom optics, high-precision metrology and quantum computing. Rabi oscillations are one of the simplest, yet potentially quite useful mechanisms for achieving such manipulation. Rabi theory establishes that in the two-level systems resonant drive leads to the periodic and complete population oscillations between the two system levels. In this paper an analytic optimization algorithm for producing Rabi-like oscillations in the general discrete many-level quantum systems is presented.

Chemical Physics, 2001

Laser control of proton dynamics in the medium-strong intramolecular hydrogen bond of picolinic a... more Laser control of proton dynamics in the medium-strong intramolecular hydrogen bond of picolinic acid N-oxide (PANO) is investigated. This work is an extension of our recent article dealing with the "statical" effects of hydrogen bonding in PANO [J. Mol. Struct. (Theochem) 500 (2000) 429-440]. A two-dimensional model potential is extracted from DFT calculations that include the proton transfer motion and the heavy atom mode. The effects of the environmental degrees of freedom were treated by means of their spectral density within the density matrix formalism. The proton dynamics is monitored over time by calculating the nonlinear optical response nonperturbatively in the driving field.

Chemical Physics, 2001

Laser control of proton dynamics in the medium-strong intramolecular hydrogen bond of picolinic a... more Laser control of proton dynamics in the medium-strong intramolecular hydrogen bond of picolinic acid N-oxide (PANO) is investigated. This work is an extension of our recent article dealing with the``statical'' eects of hydrogen bonding in PANO [J. Mol. Struct. (Theochem) 500 429±440]. A two-dimensional model potential is extracted from DFT calculations that include the proton transfer motion and the heavy atom mode. The eects of the environmental degrees of freedom were treated by means of their spectral density within the density matrix formalism. The proton dynamics is monitored over time by calculating the nonlinear optical response nonperturbatively in the driving ®eld. Ó

Combining two-color infared pump-probe spectroscopy and anharmonic force field calculations we ch... more Combining two-color infared pump-probe spectroscopy and anharmonic force field calculations we characterize the anharmonic coupling patterns between fingerprint modes and the hydrogen-bonded symmetric vNH2 stretching vibration in adenine-thymine dA20-dT20 DNA oligomers. Specifically, it is shown that the anharmonic coupling between the δNH2 bending and the vC4=O4 stretching vibration, both absorbing around 1665 cm-1, can be used to assign the vNH2 fundamental transition at 3215 cm-1 despite the broad background absorption of water.

International Journal of Quantum Chemistry, 2006

The spectroscopic proprieties of two energetically close conformers of acetylacetone have been in... more The spectroscopic proprieties of two energetically close conformers of acetylacetone have been investigated using density functional methods. The calculated anharmonic frequencies are in very satisfactory agreement with experimental data. The low height of the conversion barrier explains why the signature of both conformers can be found in the vibrational spectrum.

Journal of Physical Chemistry A, 2005

The intramolecular hydrogen bond in the enol-acethylacetone (ACAC) is investigated by performing ... more The intramolecular hydrogen bond in the enol-acethylacetone (ACAC) is investigated by performing reduced-dimensional quantum calculations. To analyze the shared proton vibrations, two sets of coordinates were employed: normal mode coordinates describing the motion in the vicinity of the most stable configuration, and internal coordinates accounting for the double minimum proton motion. It is proved that the extreme broadness of the OH-stretch band in ACAC is a consequence of the coexistence of two enol-ACAC structures: the global minimum and the transition state for rotation of the distal methyl group. Further, a ground-state tunneling splitting of 116 cm(-1) is found, and it is shown that the inclusion of the kinematic coupling is mandatory when treating large-amplitude proton motion. In the OH-stretch direction a splitting of 853 cm(-1) was predicted.

Physical Chemistry Chemical Physics, 1999

... 20, F. Duus, J. Am. ... VG Zakrzewski, JV Ortiz, JB Foresman, J. Ciolowski, BB Stefanow, A. N... more ... 20, F. Duus, J. Am. ... VG Zakrzewski, JV Ortiz, JB Foresman, J. Ciolowski, BB Stefanow, A. Nanayaklara, M. Challacombe, CY Peng, PY Ayala, W. Chen, MW Wong, JL Andres, ES Repogle, R. Gomperts, RL Martin, DJ Fox, JS Binkley, DJ Defrees, J. Baker, JP Stewart, M. Head ...

Chemical Physics, 2004

The portion of the potential energy surface (PES) of acetylacetone relevant for the intramolecula... more The portion of the potential energy surface (PES) of acetylacetone relevant for the intramolecular proton transfer reaction is studied using ab initio and DFT methods. The best estimate of the barrier governing proton transfer was found to be 3.4 kcal mol À1 at the MP4(FC)/6-311 + G(2d,2p)//MP2(FC)/6-311 + G(2d,2p) level of theory. Six stationary points on the PES were characterized as well as the reaction paths connecting these points. Special attention paid to the pathway of intramolecular proton transfer reveals that the internal rotation of the methyl group adjacent to the carbonyl group and the proton transfer reaction are consecutive processes.

Journal of Physical Chemistry A, 1998

ABSTRACT

Chemical Physics, 2008

A set of mass-weighted internal coordinates was derived and applied to the double proton transfer... more A set of mass-weighted internal coordinates was derived and applied to the double proton transfer reaction in the formic acid dimer (FAD). The coordinate set was obtained starting from the Hirschfelder "mobile" by an optimization procedure consisting of a sequence of kinematic rotations. In FAD, the optimization procedure leads to three coordinates that do change significantly along the reaction path. These coordinates span the reaction space, whereas the remaining modes are treated in a harmonic approximation. The effect that the dimer dissociative motion has on the ground and excited vibrational states dynamics was explored. In the frequency region corresponding to the symmetric OH-stretch vibration four doublets have been identified with splittings of 2.76, 0.07, 0.60, and 4.03cm-1.

Chemical Physics, 2007

There has been some controversy concerning the assignment of measured tunneling splittings for th... more There has been some controversy concerning the assignment of measured tunneling splittings for the formic acid dimer in the vibrational ground state and the asymmetric CO-stretching excited state. The discussion is intimately related to the question whether the fundamental excitation of the CO-vibration promotes or hinders tunneling. Here we will address this issue on the basis of a five-dimensional reaction space Hamiltonian which includes three large amplitude coordinates as well as two harmonic modes whose linear superposition reproduces the asymmetric CO-vibrational mode. Within density functional theory using the B3LYP functional together with a 6-311++G(3df,3pd) basis set we obtain a ground state tunneling splitting which is about 2.4 larger than the one for the CO-stretching excited state.

Chemical Physics, 2000

Laser control of a hydrogen transfer reaction in a small model system embedded in a condensed pha... more Laser control of a hydrogen transfer reaction in a small model system embedded in a condensed phase environment is investigated. The two-dimensional model comprises those features of the multi-dimensional potential energy surface of thioacetylacetone which are most relevant for the isomerization reaction from the enol to the enethiol con®guration. The in¯uence of the remaining intramolecular coordinates as well as of a possible environment is described by a spectral density within the reduced density matrix approach. Dierent forms of the driving infrared laser pulse are explored placing emphasis on their capability for competing successfully with relaxation processes. The reaction dynamics is characterized by calculating the nonlinear optical response nonperturbatively in the driving ®eld. Ó

Chemical Physics, 2003

... 10] to 4.6 kcal/mol using the PLAP1 correlation functional [8]. However, by using a sequence ... more ... 10] to 4.6 kcal/mol using the PLAP1 correlation functional [8]. However, by using a sequence of basis sets and employing several levels of electron correlation, Barone and Adamo [6] indicated ... A modified quadratic Shepard interpolation has been used to interpolate the 3D PESs ...

Journal of Physical Chemistry A, 2009

We consider the effect of isotopic labeling on the electric charge distribution and dynamics of t... more We consider the effect of isotopic labeling on the electric charge distribution and dynamics of the formic acid dimer. Our investigation is based on accurate ab initio calculations of vibrationally induced dipole moments and multidimensional quantum calculations of vibrational ground-state splittings. It is found that non-negligible dipole moments of µ ) 0.032 D and µ ) 0.021 D arise in HCOOH-DOOCD and HCOOH-DOOCH, respectively, suggesting the feasibility of microwave studies. Within the reaction surface Hamiltonian approach a ratio of splittings of 1:0.2:0.045 is predicted for HCOOH-HOOCH:HCOOH-DOOCH:HCOOD-DOOCH.

Physical Chemistry Chemical Physics, 2010

An extensive computational study of the conformational preferences of three capped dipeptides: Ac... more An extensive computational study of the conformational preferences of three capped dipeptides: Ac-Xxx-Phe-NH 2 , Xxx = Gly, Ala, Val is reported. On the basis of local second-order Møller-Plesset perturbation theory (LMP2) and DFT computations we were able to identify the experimentally observed conformers as g L -g L (gÀ) and b-turn I(g+) in Ac-Gly-Phe-NH 2 , and Ac-Ala-Phe-NH 2 , and as the closely related g L (g+)-g L (gÀ) and b-turn I(a,g+) in Ac-Val-Phe-NH 2 . In contrast to the experimental observation that peptides with bulky side chain have a propensity for b-turns, we show that in Ac-Val-Phe-NH 2 the minimum energy structure corresponds to the experimentally non detected b-strand.

European Physical Journal D, 1994

ABSTRACT

Physical Review A, 2005

State selective preparation and manipulation of discrete-level quantum systems such as atoms, mol... more State selective preparation and manipulation of discrete-level quantum systems such as atoms, molecules or quantum dots is the ultimate tool for many diverse fields such as laser control of chemical reactions, atom optics, high-precision metrology and quantum computing. Rabi oscillations are one of the simplest, yet potentially quite useful mechanisms for achieving such manipulation. Rabi theory establishes that in the two-level systems resonant drive leads to the periodic and complete population oscillations between the two system levels. In this paper an analytic optimization algorithm for producing Rabi-like oscillations in the general discrete many-level quantum system is presented.

Physical Review A, 2004

State selective preparation and manipulation of discrete-level quantum systems such as atoms, mol... more State selective preparation and manipulation of discrete-level quantum systems such as atoms, molecules or quantum dots is a the ultimate tool for many diverse fields such as laser control of chemical reactions, atom optics, high-precision metrology and quantum computing. Rabi oscillations are one of the simplest, yet potentially quite useful mechanisms for achieving such manipulation. Rabi theory establishes that in the two-level systems resonant drive leads to the periodic and complete population oscillations between the two system levels. In this paper an analytic optimization algorithm for producing Rabi-like oscillations in the general discrete many-level quantum systems is presented.

Chemical Physics, 2001

Laser control of proton dynamics in the medium-strong intramolecular hydrogen bond of picolinic a... more Laser control of proton dynamics in the medium-strong intramolecular hydrogen bond of picolinic acid N-oxide (PANO) is investigated. This work is an extension of our recent article dealing with the "statical" effects of hydrogen bonding in PANO [J. Mol. Struct. (Theochem) 500 (2000) 429-440]. A two-dimensional model potential is extracted from DFT calculations that include the proton transfer motion and the heavy atom mode. The effects of the environmental degrees of freedom were treated by means of their spectral density within the density matrix formalism. The proton dynamics is monitored over time by calculating the nonlinear optical response nonperturbatively in the driving field.

Chemical Physics, 2001

Laser control of proton dynamics in the medium-strong intramolecular hydrogen bond of picolinic a... more Laser control of proton dynamics in the medium-strong intramolecular hydrogen bond of picolinic acid N-oxide (PANO) is investigated. This work is an extension of our recent article dealing with the``statical'' eects of hydrogen bonding in PANO [J. Mol. Struct. (Theochem) 500 429±440]. A two-dimensional model potential is extracted from DFT calculations that include the proton transfer motion and the heavy atom mode. The eects of the environmental degrees of freedom were treated by means of their spectral density within the density matrix formalism. The proton dynamics is monitored over time by calculating the nonlinear optical response nonperturbatively in the driving ®eld. Ó

Combining two-color infared pump-probe spectroscopy and anharmonic force field calculations we ch... more Combining two-color infared pump-probe spectroscopy and anharmonic force field calculations we characterize the anharmonic coupling patterns between fingerprint modes and the hydrogen-bonded symmetric vNH2 stretching vibration in adenine-thymine dA20-dT20 DNA oligomers. Specifically, it is shown that the anharmonic coupling between the δNH2 bending and the vC4=O4 stretching vibration, both absorbing around 1665 cm-1, can be used to assign the vNH2 fundamental transition at 3215 cm-1 despite the broad background absorption of water.

International Journal of Quantum Chemistry, 2006

The spectroscopic proprieties of two energetically close conformers of acetylacetone have been in... more The spectroscopic proprieties of two energetically close conformers of acetylacetone have been investigated using density functional methods. The calculated anharmonic frequencies are in very satisfactory agreement with experimental data. The low height of the conversion barrier explains why the signature of both conformers can be found in the vibrational spectrum.

Journal of Physical Chemistry A, 2005

The intramolecular hydrogen bond in the enol-acethylacetone (ACAC) is investigated by performing ... more The intramolecular hydrogen bond in the enol-acethylacetone (ACAC) is investigated by performing reduced-dimensional quantum calculations. To analyze the shared proton vibrations, two sets of coordinates were employed: normal mode coordinates describing the motion in the vicinity of the most stable configuration, and internal coordinates accounting for the double minimum proton motion. It is proved that the extreme broadness of the OH-stretch band in ACAC is a consequence of the coexistence of two enol-ACAC structures: the global minimum and the transition state for rotation of the distal methyl group. Further, a ground-state tunneling splitting of 116 cm(-1) is found, and it is shown that the inclusion of the kinematic coupling is mandatory when treating large-amplitude proton motion. In the OH-stretch direction a splitting of 853 cm(-1) was predicted.

Physical Chemistry Chemical Physics, 1999

... 20, F. Duus, J. Am. ... VG Zakrzewski, JV Ortiz, JB Foresman, J. Ciolowski, BB Stefanow, A. N... more ... 20, F. Duus, J. Am. ... VG Zakrzewski, JV Ortiz, JB Foresman, J. Ciolowski, BB Stefanow, A. Nanayaklara, M. Challacombe, CY Peng, PY Ayala, W. Chen, MW Wong, JL Andres, ES Repogle, R. Gomperts, RL Martin, DJ Fox, JS Binkley, DJ Defrees, J. Baker, JP Stewart, M. Head ...

Chemical Physics, 2004

The portion of the potential energy surface (PES) of acetylacetone relevant for the intramolecula... more The portion of the potential energy surface (PES) of acetylacetone relevant for the intramolecular proton transfer reaction is studied using ab initio and DFT methods. The best estimate of the barrier governing proton transfer was found to be 3.4 kcal mol À1 at the MP4(FC)/6-311 + G(2d,2p)//MP2(FC)/6-311 + G(2d,2p) level of theory. Six stationary points on the PES were characterized as well as the reaction paths connecting these points. Special attention paid to the pathway of intramolecular proton transfer reveals that the internal rotation of the methyl group adjacent to the carbonyl group and the proton transfer reaction are consecutive processes.

Journal of Physical Chemistry A, 1998

ABSTRACT

Chemical Physics, 2008

A set of mass-weighted internal coordinates was derived and applied to the double proton transfer... more A set of mass-weighted internal coordinates was derived and applied to the double proton transfer reaction in the formic acid dimer (FAD). The coordinate set was obtained starting from the Hirschfelder "mobile" by an optimization procedure consisting of a sequence of kinematic rotations. In FAD, the optimization procedure leads to three coordinates that do change significantly along the reaction path. These coordinates span the reaction space, whereas the remaining modes are treated in a harmonic approximation. The effect that the dimer dissociative motion has on the ground and excited vibrational states dynamics was explored. In the frequency region corresponding to the symmetric OH-stretch vibration four doublets have been identified with splittings of 2.76, 0.07, 0.60, and 4.03cm-1.

Chemical Physics, 2007

There has been some controversy concerning the assignment of measured tunneling splittings for th... more There has been some controversy concerning the assignment of measured tunneling splittings for the formic acid dimer in the vibrational ground state and the asymmetric CO-stretching excited state. The discussion is intimately related to the question whether the fundamental excitation of the CO-vibration promotes or hinders tunneling. Here we will address this issue on the basis of a five-dimensional reaction space Hamiltonian which includes three large amplitude coordinates as well as two harmonic modes whose linear superposition reproduces the asymmetric CO-vibrational mode. Within density functional theory using the B3LYP functional together with a 6-311++G(3df,3pd) basis set we obtain a ground state tunneling splitting which is about 2.4 larger than the one for the CO-stretching excited state.

Chemical Physics, 2000

Laser control of a hydrogen transfer reaction in a small model system embedded in a condensed pha... more Laser control of a hydrogen transfer reaction in a small model system embedded in a condensed phase environment is investigated. The two-dimensional model comprises those features of the multi-dimensional potential energy surface of thioacetylacetone which are most relevant for the isomerization reaction from the enol to the enethiol con®guration. The in¯uence of the remaining intramolecular coordinates as well as of a possible environment is described by a spectral density within the reduced density matrix approach. Dierent forms of the driving infrared laser pulse are explored placing emphasis on their capability for competing successfully with relaxation processes. The reaction dynamics is characterized by calculating the nonlinear optical response nonperturbatively in the driving ®eld. Ó