Robert G. Littlejohn

5.6k total citations
91 papers, 3.9k citations indexed

About

Robert G. Littlejohn is a scholar working on Atomic and Molecular Physics, and Optics, Statistical and Nonlinear Physics and Spectroscopy. According to data from OpenAlex, Robert G. Littlejohn has authored 91 papers receiving a total of 3.9k indexed citations (citations by other indexed papers that have themselves been cited), including 56 papers in Atomic and Molecular Physics, and Optics, 48 papers in Statistical and Nonlinear Physics and 22 papers in Spectroscopy. Recurrent topics in Robert G. Littlejohn's work include Quantum chaos and dynamical systems (44 papers), Spectroscopy and Quantum Chemical Studies (17 papers) and Advanced Chemical Physics Studies (17 papers). Robert G. Littlejohn is often cited by papers focused on Quantum chaos and dynamical systems (44 papers), Spectroscopy and Quantum Chemical Studies (17 papers) and Advanced Chemical Physics Studies (17 papers). Robert G. Littlejohn collaborates with scholars based in United States, United Kingdom and Italy. Robert G. Littlejohn's co-authors include Matthias Reinsch, Stephen C. Creagh, John R. Cary, J. M. Robbins, Kevin Mitchell, Vincenz̊o Aquilanti, Eric J. Heller, Joseph E. Subotnik, Daniel Huber and Stefan Weigert and has published in prestigious journals such as Physical Review Letters, The Journal of Chemical Physics and Reviews of Modern Physics.

In The Last Decade

Robert G. Littlejohn

91 papers receiving 3.8k citations

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name h Career Trend Papers Cites
Robert G. Littlejohn United States 29 1.9k 1.6k 1.5k 1.0k 455 91 3.9k
Allan N. Kaufman United States 32 1.9k 1.0× 1.8k 1.2× 1.8k 1.2× 1.3k 1.3× 104 0.2× 128 4.3k
Alfred D. Shapere United States 25 1.5k 0.8× 1.1k 0.7× 2.1k 1.4× 1.3k 1.3× 123 0.3× 38 4.2k
Aurel Bulgac United States 39 3.0k 1.6× 811 0.5× 1.3k 0.9× 433 0.4× 243 0.5× 144 4.5k
T. M. O’Neil United States 37 3.6k 1.9× 753 0.5× 2.5k 1.6× 2.2k 2.2× 259 0.6× 120 6.1k
F. Calogero Italy 37 3.1k 1.6× 5.2k 3.3× 932 0.6× 332 0.3× 587 1.3× 364 7.9k
R. F. O’Connell United States 32 4.9k 2.5× 2.2k 1.4× 737 0.5× 1.3k 1.3× 244 0.5× 284 6.8k
Y. Alhassid United States 45 3.9k 2.0× 2.8k 1.8× 2.9k 1.9× 157 0.2× 846 1.9× 192 6.2k
Michael Martin Nieto United States 39 4.6k 2.4× 2.4k 1.5× 1.5k 1.0× 1.8k 1.8× 212 0.5× 184 6.8k
J. J. M. Verbaarschot United States 49 2.6k 1.3× 2.9k 1.8× 4.6k 3.0× 347 0.3× 401 0.9× 163 7.3k
Lowell S. Brown United States 40 3.1k 1.6× 1.1k 0.7× 3.6k 2.3× 1.2k 1.2× 468 1.0× 105 6.0k

Countries citing papers authored by Robert G. Littlejohn

Since Specialization
Citations

This map shows the geographic impact of Robert G. Littlejohn's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Robert G. Littlejohn with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Robert G. Littlejohn more than expected).

Fields of papers citing papers by Robert G. Littlejohn

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Robert G. Littlejohn. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Robert G. Littlejohn. The network helps show where Robert G. Littlejohn may publish in the future.

Co-authorship network of co-authors of Robert G. Littlejohn

This figure shows the co-authorship network connecting the top 25 collaborators of Robert G. Littlejohn. A scholar is included among the top collaborators of Robert G. Littlejohn based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with Robert G. Littlejohn. Robert G. Littlejohn is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
Tao, Zhen, et al.. (2025). Symmetry breaking as predicted by a phase space Hamiltonian with a spin Coriolis potential. The Journal of Chemical Physics. 162(24). 5 indexed citations
2.
Littlejohn, Robert G., et al.. (2025). A Phase-Space View of Vibrational Energies without the Born–Oppenheimer Framework. Journal of Chemical Theory and Computation. 21(6). 2880–2893. 5 indexed citations
3.
Littlejohn, Robert G., et al.. (2025). Recovering Exact Vibrational Energies within a Phase Space Electronic Structure Framework. Journal of Chemical Theory and Computation. 21(19). 9470–9482. 1 indexed citations
4.
Tao, Zhen, et al.. (2025). A Phase-Space Electronic Hamiltonian for Molecules in a Static Magnetic Field. I: Conservation of Total Pseudomomentum and Angular Momentum. The Journal of Physical Chemistry A. 129(20). 4555–4572. 2 indexed citations
5.
Tao, Zhen, et al.. (2024). Practical phase-space electronic Hamiltonians for ab initio dynamics. The Journal of Chemical Physics. 160(12). 15 indexed citations
6.
Tao, Zhen, et al.. (2024). A Phase-Space Electronic Hamiltonian For Vibrational Circular Dichroism. Journal of Chemical Theory and Computation. 9 indexed citations
7.
Tao, Zhen, et al.. (2024). An electronic phase-space Hamiltonian approach for electronic current density and vibrational circular dichroism. The Journal of Chemical Physics. 161(20). 6 indexed citations
8.
Qiu, Tian, et al.. (2024). A simple one-electron expression for electron rotational factors. The Journal of Chemical Physics. 160(12). 13 indexed citations
9.
Littlejohn, Robert G., et al.. (2024). Linear and angular momentum conservation in surface hopping methods. The Journal of Chemical Physics. 160(2). 11 indexed citations
10.
Athavale, Vishikh, et al.. (2023). Surface hopping, electron translation factors, electron rotation factors, momentum conservation, and size consistency. The Journal of Chemical Physics. 159(11). 11 indexed citations
11.
Aquilanti, Vincenz̊o, Andrea Lombardi, & Robert G. Littlejohn. (2003). Hyperspherical harmonics for polyatomic systems: basis set for collective motions. Theoretical Chemistry Accounts. 111(2-6). 400–406. 22 indexed citations
12.
Littlejohn, Robert G., et al.. (2002). Phase space deformation and basis set optimization. Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics. 65(2). 26703–26703. 11 indexed citations
13.
Mitchell, Kevin & Robert G. Littlejohn. (2000). Boundary conditions on internal three-body wave functions. Physical Review A. 61(4). 9 indexed citations
14.
Mitchell, Kevin & Robert G. Littlejohn. (1999). Kinematic orbits and the structure of the internal space for systems of five or more \nbodies. eScholarship (California Digital Library). 12 indexed citations
15.
Littlejohn, Robert G. & Roland Winston. (1993). Corrections to classical radiometry. TuV.2–TuV.2. 3 indexed citations
16.
Littlejohn, Robert G. & Roland Winston. (1993). Corrections to classical radiometry. Journal of the Optical Society of America A. 10(9). 2024–2024. 34 indexed citations
17.
Littlejohn, Robert G., et al.. (1991). Geometric phases in the asymptotic theory of coupled wave equations. Physical Review A. 44(8). 5239–5256. 133 indexed citations
18.
Feingold, Mario, et al.. (1990). Scars in billiards: The phase space approach. Physics Letters A. 146(4). 199–203. 24 indexed citations
19.
Robbins, J. M., Stephen C. Creagh, & Robert G. Littlejohn. (1989). Complex periodic orbits in the rotational spectrum of molecules: The example ofSF6. Physical review. A, General physics. 39(6). 2838–2854. 27 indexed citations
20.
Littlejohn, Robert G.. (1985). Differential forms and canonical variables for drift motion in toroidal geometry. The Physics of Fluids. 28(6). 2015–2016. 47 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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