Ralph E. Christoffersen

2.6k total citations
77 papers, 1.9k citations indexed

About

Ralph E. Christoffersen is a scholar working on Atomic and Molecular Physics, and Optics, Physical and Theoretical Chemistry and Spectroscopy. According to data from OpenAlex, Ralph E. Christoffersen has authored 77 papers receiving a total of 1.9k indexed citations (citations by other indexed papers that have themselves been cited), including 49 papers in Atomic and Molecular Physics, and Optics, 27 papers in Physical and Theoretical Chemistry and 25 papers in Spectroscopy. Recurrent topics in Ralph E. Christoffersen's work include Advanced Chemical Physics Studies (35 papers), Spectroscopy and Quantum Chemical Studies (25 papers) and Photochemistry and Electron Transfer Studies (13 papers). Ralph E. Christoffersen is often cited by papers focused on Advanced Chemical Physics Studies (35 papers), Spectroscopy and Quantum Chemical Studies (25 papers) and Photochemistry and Electron Transfer Studies (13 papers). Ralph E. Christoffersen collaborates with scholars based in United States, United Kingdom and China. Ralph E. Christoffersen's co-authors include Gerald M. Maggiora, Lester L. Shipman, James D. Petke, G. G. Hall, Dale Spangler, J. Joseph Marr, B. Vernon Cheney, David J. Duchamp, Tetsuro Oie and Cary F. Chabalowski and has published in prestigious journals such as Proceedings of the National Academy of Sciences, Journal of the American Chemical Society and The Journal of Chemical Physics.

In The Last Decade

Ralph E. Christoffersen

77 papers receiving 1.8k citations

Peers — A (Enhanced Table)

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

Name h Career Trend Papers Cites
Ralph E. Christoffersen United States 26 1.1k 663 622 533 384 77 1.9k
Giuseppe Del Re Italy 18 917 0.9× 563 0.8× 263 0.4× 409 0.8× 332 0.9× 85 1.9k
M. Plato Germany 26 857 0.8× 766 1.2× 1.0k 1.7× 580 1.1× 353 0.9× 69 2.1k
Gad Fischer Australia 23 894 0.8× 571 0.9× 221 0.4× 307 0.6× 540 1.4× 91 1.6k
Jon Applequist United States 29 1.2k 1.2× 523 0.8× 1.2k 2.0× 546 1.0× 868 2.3× 73 3.0k
Ichiro Hanazaki Japan 29 1.1k 1.1× 572 0.9× 272 0.4× 351 0.7× 634 1.7× 118 2.4k
G. Berthier France 24 1.0k 1.0× 588 0.9× 223 0.4× 368 0.7× 526 1.4× 106 1.8k
G. Corongiu Italy 30 1.9k 1.7× 611 0.9× 786 1.3× 451 0.8× 673 1.8× 95 2.9k
Jan Davidsson Sweden 26 728 0.7× 543 0.8× 381 0.6× 717 1.3× 492 1.3× 59 1.9k
David L. Beveridge United States 29 1.0k 1.0× 665 1.0× 1.5k 2.3× 390 0.7× 404 1.1× 49 2.9k
Daniel L. Severance United States 20 773 0.7× 543 0.8× 636 1.0× 459 0.9× 481 1.3× 30 2.3k

Countries citing papers authored by Ralph E. Christoffersen

Since Specialization
Citations

This map shows the geographic impact of Ralph E. Christoffersen'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 Ralph E. Christoffersen with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Ralph E. Christoffersen more than expected).

Fields of papers citing papers by Ralph E. Christoffersen

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Ralph E. Christoffersen. 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 Ralph E. Christoffersen. The network helps show where Ralph E. Christoffersen may publish in the future.

Co-authorship network of co-authors of Ralph E. Christoffersen

This figure shows the co-authorship network connecting the top 25 collaborators of Ralph E. Christoffersen. A scholar is included among the top collaborators of Ralph E. Christoffersen 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 Ralph E. Christoffersen. Ralph E. Christoffersen 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.
Christoffersen, Ralph E.. (2009). Ab initio calculations on large molecules using molecular fragments characterization of anthracene and phenanthrene. International Journal of Quantum Chemistry. 7(S7). 169–179. 2 indexed citations
2.
Oie, Tetsuro, Gerald M. Maggiora, & Ralph E. Christoffersen. (2009). Structural characterization of a special-pair chlorophyll dimer model of P700. International Journal of Quantum Chemistry. 22(S9). 157–171. 1 indexed citations
3.
Christoffersen, Ralph E.. (1997). Translating genomics information into therapeutics: A key role for oligonucleotides. Nature Biotechnology. 15(6). 483–484. 17 indexed citations
4.
Christoffersen, Ralph E. & J. Joseph Marr. (1995). Ribozymes as Human Therapeutic Agents. Journal of Medicinal Chemistry. 38(12). 2023–2037. 92 indexed citations
5.
Christoffersen, Ralph E.. (1989). Basic Principles and Techniques of Molecular Quantum Mechanics. 15 indexed citations
6.
Cheney, B. Vernon, David J. Duchamp, & Ralph E. Christoffersen. (1983). Structure-activity correlations for a series of antiallergy agents. 2. Geometric and electronic characterization of some oxamic and dioxamic acids. Journal of Medicinal Chemistry. 26(5). 719–725. 6 indexed citations
7.
8.
Spangler, Dale & Ralph E. Christoffersen. (1980). Ab initio calculations on large molecules using molecular fragments. Generalization of the molecular fragment basis at the minimum basis set level. International Journal of Quantum Chemistry. 17(6). 1075–1097. 20 indexed citations
9.
Petke, James D., Gerald M. Maggiora, Lester L. Shipman, & Ralph E. Christoffersen. (1980). STEREOELECTRONIC PROPERTIES OF PHOTOSYNTHETIC AND RELATED SYSTEMS—VIII. AB INITIO QUANTUM MECHANICAL CHARACTERIZATION OF THE ELECTRONIC STRUCTURE AND SPECTRUM OF THE BACTERIOPHEOPHORBIDE a ANION RADICAL. Photochemistry and Photobiology. 32(5). 661–667. 10 indexed citations
10.
Petke, James D., Gerald M. Maggiora, Lester L. Shipman, & Ralph E. Christoffersen. (1978). Stereoelectronic properties of photosynthetic and related systems. Journal of Molecular Spectroscopy. 73(2). 311–331. 51 indexed citations
11.
Cheney, B. Vernon, John B. Wright, C. M. Hall, Herbert G. Johnson, & Ralph E. Christoffersen. (1978). Structure-activity correlations for a series of antiallergy agents. Oxanilic, quinaldic, and benzopyran-2-carboxylic acids. Journal of Medicinal Chemistry. 21(9). 936–940. 11 indexed citations
12.
Christoffersen, Ralph E., et al.. (1976). The development of quantum mechanical solvent effect models. Macroscopic electrostatic contributions. Journal of the American Chemical Society. 98(23). 7191–7197. 95 indexed citations
13.
Chabalowski, Cary F., et al.. (1976). Ab initio calculations on large molecules using molecular fragments. Configuration interaction calculations on the ground and lower excited states of carbazole. Journal of the American Chemical Society. 98(16). 4794–4801. 28 indexed citations
14.
Spangler, Dale, et al.. (1975). Ab initio calculations on large molecules using molecular fragments. Preliminary investigation of ethyl chlorophyllide a and related molecules. Chemical Physics Letters. 36(4). 427–431. 23 indexed citations
15.
Christoffersen, Ralph E., et al.. (1975). Explicitly correlated configuration interaction wavefunctions using spherical Gaussians. Formulation and initial application to LiH. The Journal of Chemical Physics. 62(5). 1992–1993. 19 indexed citations
16.
Shipman, Lester L. & Ralph E. Christoffersen. (1972). Ab initio calculations on large molecules using molecular fragments. Initial P-matrices for scf calculations. Chemical Physics Letters. 15(4). 469–474. 24 indexed citations
17.
Cheney, B. Vernon & Ralph E. Christoffersen. (1972). Ab Initio Calculations on Large Molecules Using Molecular Fragments. Oxygen-Containing Molecules. The Journal of Chemical Physics. 56(7). 3503–3518. 25 indexed citations
18.
Christoffersen, Ralph E. & Klaus Ruedenberg. (1968). Hybrid Integrals over Slater-Type Atomic Orbitals. The Journal of Chemical Physics. 49(10). 4285–4292. 21 indexed citations
19.
Christoffersen, Ralph E. & Harrison Shull. (1968). Nature of the Two-Electron Chemical Bond. VII. Multicenter Bonds and H3+. The Journal of Chemical Physics. 48(4). 1790–1797. 23 indexed citations
20.
Christoffersen, Ralph E. & Klaus Ruedenberg. (1967). Two-Center Hybrid Integrals between Slater-Type Atomic Orbitals. The Journal of Chemical Physics. 47(5). 1855–1856. 5 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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