U. Öpik

2.3k total citations · 2 hit papers
21 papers, 2.0k citations indexed

About

U. Öpik is a scholar working on Atomic and Molecular Physics, and Optics, Spectroscopy and Electrical and Electronic Engineering. According to data from OpenAlex, U. Öpik has authored 21 papers receiving a total of 2.0k indexed citations (citations by other indexed papers that have themselves been cited), including 20 papers in Atomic and Molecular Physics, and Optics, 5 papers in Spectroscopy and 5 papers in Electrical and Electronic Engineering. Recurrent topics in U. Öpik's work include Atomic and Molecular Physics (12 papers), Advanced Chemical Physics Studies (12 papers) and Advanced Physical and Chemical Molecular Interactions (4 papers). U. Öpik is often cited by papers focused on Atomic and Molecular Physics (12 papers), Advanced Chemical Physics Studies (12 papers) and Advanced Physical and Chemical Molecular Interactions (4 papers). U. Öpik collaborates with scholars based in United Kingdom and United States. U. Öpik's co-authors include M. H. L. Pryce, R. A. Sack, Hugh Christopher Longuet-Higgins, R. F. Wood, D. R. Bates, M. R. Flannery, G. Poots, T.H. Thomas and C. Laughlin and has published in prestigious journals such as Computer Physics Communications, Molecular Physics and Solid State Communications.

In The Last Decade

U. Öpik

20 papers receiving 1.9k citations

Hit Papers

align trajectories

What are hit papers?

Hit papers significantly outperform the citation benchmark for their cohort. A paper qualifies if it has ≥500 total citations, achieves ≥1.5× the top-1% citation threshold for papers in the same subfield and year (this is the minimum needed to enter the top 1%, not the average within it), or reaches the top citation threshold in at least one of its specific research topics.

Studies of the Jahn-Teller effect .II. The dynamical problem

1958 785 citations Hugh Christopher Longuet-Higgins, U. Öpik et al. Proceedings of the Royal Society of London A Mathematical and Physical Sciences profile →
Studies of the Jahn-Teller effect. I. A survey of the static problem

1957 673 citations U. Öpik, M. H. L. Pryce Proceedings of the Royal Society of London A Mathematical and Physical Sciences profile →

Peers — A (Enhanced Table)

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

Name	h						Papers	Cites
U. Öpik United Kingdom	12	1.4k	593	478	344	272	21	2.0k
Brian R. Judd United States	19	1.2k 0.9×	1.1k 1.8×	366 0.8×	308 0.9×	291 1.1×	27	2.3k
N. W. Winter United States	25	1.4k 1.0×	554 0.9×	168 0.4×	308 0.9×	485 1.8×	58	2.0k
J. Farges France	23	1.6k 1.1×	983 1.7×	533 1.1×	216 0.6×	157 0.6×	81	2.8k
Laurens Jansen Switzerland	26	895 0.7×	385 0.6×	362 0.8×	289 0.8×	229 0.8×	107	1.7k
T. P. Das United States	28	1.7k 1.3×	1.1k 1.9×	474 1.0×	256 0.7×	390 1.4×	194	3.1k
Gulzari Malli Canada	26	1.8k 1.3×	414 0.7×	269 0.6×	542 1.6×	313 1.2×	112	2.2k
Keith Clemenger United States	8	2.1k 1.5×	1.5k 2.6×	341 0.7×	495 1.4×	212 0.8×	9	3.1k
G. L. Goodman United States	26	1.1k 0.8×	1.3k 2.3×	642 1.3×	737 2.1×	309 1.1×	71	2.8k
Anders Heiberg Norway	8	1.2k 0.9×	564 1.0×	275 0.6×	312 0.9×	375 1.4×	17	1.8k
R. A. Satten United States	20	713 0.5×	1.7k 2.9×	301 0.6×	488 1.4×	202 0.7×	37	2.3k

Countries citing papers authored by U. Öpik

Since Specialization

Citations

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

Fields of papers citing papers by U. Öpik

Since Specialization

Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by U. Öpik. 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 U. Öpik. The network helps show where U. Öpik may publish in the future.

Co-authorship network of co-authors of U. Öpik

This figure shows the co-authorship network connecting the top 25 collaborators of U. Öpik. A scholar is included among the top collaborators of U. Öpik 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 U. Öpik. U. Öpik is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

Sort: Min cites: Since: Top N: Style:

20 of 20 papers shown

Öpik, U.. (1987). A program to set up systems of orthogonal polynomials. Computer Physics Communications. 46(2). 263–296.

Öpik, U., et al.. (1984). An impact-parameter method for heavy-particle collisions involving one electron. II. Attempts to improve the accuracy, and results on He²⁺-H collisions. Journal of Physics B Atomic and Molecular Physics. 17(5). 857–865. 1 indexed citations

Öpik, U., et al.. (1979). Excitation and charge transfer to the 2s and 2p states in H⁺-H collisions in the energy range 49 to 125 keV. Journal of Physics B Atomic and Molecular Physics. 12(22). L685–L688. 6 indexed citations

Öpik, U. & R. F. Wood. (1969). Point Defects in Ionic Crystals. I. Methods of Calculating the Electronic Structure. Physical Review. 179(3). 772–782. 41 indexed citations

Öpik, U.. (1969). The interpretation of the energies of the 2D states of the lithium atom in terms of the polarization of the core by the outer electron. Journal of Physics B Atomic and Molecular Physics. 2(12). 1411–1412. 7 indexed citations

Wood, R. F. & U. Öpik. (1969). Point Defects in Ionic Crystals. II. TheFCenter in KCl, KBr, KI, and NaCl. Physical Review. 179(3). 783–796. 87 indexed citations

Bates, D. R. & U. Öpik. (1968). Undulations in the photoionization cross section curves of molecules. Journal of Physics B Atomic and Molecular Physics. 1(4). 543–547. 47 indexed citations

Öpik, U., et al.. (1967). The polarization of a closed-shell core of an atomic system by an outer electron I. A correction to the adiabatic approximation. Proceedings of the Physical Society. 92(3). 556–565. 63 indexed citations

Öpik, U.. (1967). The polarization of a closed-shell core of an atomic system by an outer electron II. Evaluation of the polarizabilities from observed spectra. Proceedings of the Physical Society. 92(3). 566–572. 55 indexed citations

10.

Öpik, U.. (1967). A simple method for calculating van der Waals interactions. Proceedings of the Physical Society. 92(3). 573–576. 11 indexed citations

11.

Wood, R. F. & U. Öpik. (1967). Electronic Structure of theUCenter. I. Optical Absorption and Lattice Relaxation. Physical Review. 162(3). 736–745. 22 indexed citations

12.

Öpik, U. & T.H. Thomas. (1966). An application of the Pariser-Parr approximation to the nitrogen molecule. Molecular Physics. 10(3). 289–296. 4 indexed citations

13.

Flannery, M. R. & U. Öpik. (1965). The photoionization of the hydrogen molecule from the ground electronic and vibrational state. Proceedings of the Physical Society. 86(3). 491–500. 55 indexed citations

14.

Laughlin, C. & U. Öpik. (1964). Variational calculations on a substitutional Ca+ impurity in the sodium chloride lattice. Solid State Communications. 2(10). 309–311. 2 indexed citations

15.

Öpik, U., et al.. (1964). A simplified hartree-fock procedure for atoms with two electrons outside closed shells. Proceedings of the Physical Society. 83(4). 541–547. 49 indexed citations

16.

Öpik, U.. (1961). Mean energies of hybridized valence states. Molecular Physics. 4(6). 505–508. 10 indexed citations

17.

Longuet-Higgins, Hugh Christopher, U. Öpik, M. H. L. Pryce, & R. A. Sack. (1958). Studies of the Jahn-Teller effect .II. The dynamical problem. Proceedings of the Royal Society of London A Mathematical and Physical Sciences. 244(1236). 1–16. 785 indexed citations breakdown →

18.

Öpik, U. & M. H. L. Pryce. (1957). Studies of the Jahn-Teller effect. I. A survey of the static problem. Proceedings of the Royal Society of London A Mathematical and Physical Sciences. 238(1215). 425–447. 673 indexed citations breakdown →

19.

Öpik, U.. (1955). The Layzer Approximation for the Treatment of Collisions of Electrons with Atoms. Proceedings of the Physical Society Section A. 68(5). 377–385. 1 indexed citations

20.

Bates, D. R., U. Öpik, & G. Poots. (1953). Properties of the Hydrogen Molecular Ion II: Photo-Ionization from the 1s _g, 2s _gand 3s _gStates. Proceedings of the Physical Society Section A. 66(12). 1113–1123. 51 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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