We investigate and analyze the vibrational properties, including H/D isotope effects, in a fundamental organic hydrogenbonded system using multiple experimental (infrared multiple photon dissociation and argon-tagged action spectroscopy) and computational techniques. The differences between simulated cluster spectroscopy of the isotopically labeled systemswere analyzed from a system-bath coupling perspective. We have found that the energy repartitioning between modes leadsto a complex spectral evolution as a function of temperature.
Vibrational spectroscopy and energy redistribution in hydrogen bonded systems
Representative publications
82
A reformulation of all ONIOM-type molecular fragmentation approaches using graph theory-based projection operators: Applications to dynamics, molecular potential surfaces, and machine learning and quantum computing
S. S. Iyengar, Timothy C. Ricard, Xiao Zhu, “A reformulation of all ONIOM-type molecular fragmentation approaches using graph theory-based projection operators: Applications to dynamics, molecular potential surfaces, and machine learning and quantum computing” J. Phys. Chem. A, ASAP (2023). J. Phys. Chem. A 128, 466 (2024).
Summary: We present a graph-theory-based reformulation of all ONIOM-based molecular fragmentation methods. We discuss applications to (a) accurate post-Hartree–Fock AIMD that can be conducted at DFT cost for medium-sized systems, (b) hybrid DFT condensed-phase studies at the cost of pure density functionals, (c) reduced cost on-the-fly large basis gas-phase AIMD and condensed-phase studies, (d) post-Hartree–Fock-level potential surfaces at DFT cost to obtain quantum nuclear effects, and (e) novel transfer machine learning protocols derived from these measures. Additionally, in previous work, the unifying strategy discussed here has been used to construct new quantum computing algorithms. Thus, we conclude that this reformulation is robust and accurate.
58
Proton relays in anomalous carbocations dictate spectroscopy, stability and mechanisms: Case studies on C 2H 5+ and C 3H 3+
L. M. Sager and S. S. Iyengar, "Proton relays in anomalous carbocations dictate spectroscopy, stability and mechanisms: Case studies on C 2H 5+ and C 3H 3+" Phys. Chem. Chem. Phys. 19, 27801 (2017).
55
A Grotthuss-like proton shuttle in the anomalous C 2H 3+ Carbocation: Energetic and vibrational properties for isotopologues
J. Li, A. B. Pacheco, K. Raghavachari and S. S. Iyengar, "A Grotthuss-like proton shuttle in the anomalous C 2H 3+ Carbocation: Energetic and vibrational properties for isotopologues" Phys. Chem. Chem. Phys. 18, 29395 (2016). (Click here for supporting information.)
47
Constructing periodic phase space orbits from ab initio molecular dynamics trajectories to analyze vibrational spectra: case study of the Zundel (H5O2+) cation
S. M. Dietrick and S. S. Iyengar, "Constructing periodic phase space orbits from ab initio molecular dynamics trajectories to analyze vibrational spectra: case study of the Zundel (H5O2+) cation", In Press. J. Chem. Theory and Comp. 8, 4876 (2012).
45
'Pump-probe' atom-centered density matrix propagation studies to gauge anharmonicity and energy repartitioning in atmospheric reactive adducts: Case study of the OH + Isoprene and OH + Butadiene reaction intermediates
A. B. Pacheco, S. M. Dietrick, P. S. Stevens and S. S. Iyengar, "'Pump-probe' atom-centered density matrix propagation studies to gauge anharmonicity and energy repartitioning in atmospheric reactive adducts: Case study of the OH + Isoprene and OH + Butadiene reaction intermediates", J. Phys. Chem. A 116, 4108 (2012).
44
The influence of water on anharmonicity, stability and vibrational energy distribution of hydrogen-bonded adducts in atmospheric reactions: Case study of Hydroxy Isoprene using ab-initio Molecular Dynamics
S. M. Dietrick, A. B. Pacheco, P. Phatak, P. S. Stevens and S. S. Iyengar, "The influence of water on anharmonicity, stability and vibrational energy distribution of hydrogen-bonded adducts in atmospheric reactions: Case study of Hydroxy Isoprene using ab-initio Molecular Dynamics", J. Phys. Chem. A 116, 399 (2012).
38
Isotope dependent, temperature regulated, energy repartitioning in a low-barrier, short-strong hydrogen bonded cluster
X. Li, J. Oomens, J. R. Eyler, D. T. Moore, S. S. Iyengar, "Isotope dependent, temperature regulated, energy repartitioning in a low-barrier, short-strong hydrogen bonded cluster" J. Chem. Phys. 132, 244301 (2010).
36
Computing vibrational properties in hydrogen bonded systems using Quantum wavepacket ab initio molecular dynamics
S. S. Iyengar, "Computing vibrational properties in hydrogen bonded systems using Quantum wavepacket ab initio molecular dynamics" Int. J. Quant. Chem. 109, 3798 (2009).
32
Insights from first principles molecular dynamics studies towards infra-red multiple-photon and single-photon action spectroscopy: Case study of the proton-bound di-methyl ether dimer
X. Li, D. T. Moore and S. S. Iyengar, "Insights from first principles molecular dynamics studies towards infra-red multiple-photon and single-photon action spectroscopy: Case study of the proton-bound di-methyl ether dimer". J. Chem. Phys. 128, 184308 (2008).
31
The study of dynamically averaged vibrational spectroscopy of atmospherically relevant clusters using ab initio molecular dynamics in conjunction with quantum wavepackets
S. S. Iyengar, X. Li and I. Sumner "The study of dynamically averaged vibrational spectroscopy of atmospherically relevant clusters using ab initio molecular dynamics in conjunction with quantum wavepackets". Adv. Quant. Chem. 55, 333 (2008).
29
Quantum Wavepacket Ab Initio Molecular Dynamics: An approach for computing dynamically averaged vibrational spectra including critical nuclear quantum effects
I. Sumner and S. S. Iyengar "Quantum Wavepacket Ab Initio Molecular Dynamics: An approach for computing dynamically averaged vibrational spectra including critical nuclear quantum effects". J. Phys. Chem. A, 111, 10313-10324 (2007).
28
Further analysis of the dynamically averaged vibrational spectrum for the 'magic' protonated 21-water cluster
S. S. Iyengar "Further analysis of the dynamically averaged vibrational spectrum for the 'magic' protonated 21-water cluster". J. Chem. Phys. 126, 216101 (2007).
27
Can the four-coordinated, penta-valent oxygen in hydroxide water clusters be detected through experimental vibrational spectroscopy?
X. Li, V. E. Teige and S. S. Iyengar "Can the four-coordinated, penta-valent oxygen in hydroxide water clusters be detected through experimental vibrational spectroscopy?". J. Phys. Chem. A 111, 4815-4820 (2007).
21
The Properties of Ion-Water Clusters. I. The Protonated 21-Water Cluster
S. S. Iyengar, M. K. Petersen, C. J. Burnham, T. J. F. Day, V. E. Teige and G. A. Voth, "The Properties of Ion-Water Clusters. I. The Protonated 21-Water Cluster". J. Chem. Phys. 123, 084309 (2005)
20
On the Amphiphilic Behavior of the Hydrated Proton: An Ab Initio Molecular Dynamics Study
S. S. Iyengar, T. J. F. Day, and G. A. Voth, "On the Amphiphilic Behavior of the Hydrated Proton: An Ab Initio Molecular Dynamics Study". Int. J. Mass Spectrometry 241, 197-204 (2005).
18
The Hydrated Proton at the Water Liquid/Vapor Interface
M. K. Petersen, S. S. Iyengar, C. J. Burnham, T. J. F. Day, and G. A. Voth, "The Hydrated Proton at the Water Liquid/Vapor Interface". J. Phys. Chem. B 108, 14804 (2004).
4
Symmetry-Adapted Distributed Approximating Functionals: Theory and application to the ro-vibrational states of H 3+
S. S. Iyengar, G. A. Parker, D. J. Kouri, D. K. Hoffman, "Symmetry-Adapted Distributed Approximating Functionals: Theory and application to the ro-vibrational states of H 3+". J. Chem. Phys. 110, 10283 (1999).